diff --git a/libguac/include/client-handlers.h b/libguac/include/client-handlers.h
index de7603ae..8ad48435 100644
--- a/libguac/include/client-handlers.h
+++ b/libguac/include/client-handlers.h
@@ -40,6 +40,7 @@
 
 #include "client.h"
 #include "protocol.h"
+#include "error.h"
 
 /**
  * Provides initial handler functions and a lookup structure for automatically
@@ -52,7 +53,7 @@
 /**
  * Internal handler for Guacamole instructions.
  */
-typedef int __guac_instruction_handler(guac_client* client, guac_instruction* copied);
+typedef guac_status __guac_instruction_handler(guac_client* client, guac_instruction* copied);
 
 /**
  * Structure mapping an instruction opcode to an instruction handler.
@@ -76,35 +77,35 @@ typedef struct __guac_instruction_handler_mapping {
  * is received, this handler will be called. Sync instructions are automatically
  * handled, thus there is no client handler for sync instruction.
  */
-int __guac_handle_sync(guac_client* client, guac_instruction* instruction);
+guac_status __guac_handle_sync(guac_client* client, guac_instruction* instruction);
 
 /**
  * Internal initial handler for the mouse instruction. When a mouse instruction
  * is received, this handler will be called. The client's mouse handler will
  * be invoked if defined.
  */
-int __guac_handle_mouse(guac_client* client, guac_instruction* instruction);
+guac_status __guac_handle_mouse(guac_client* client, guac_instruction* instruction);
 
 /**
  * Internal initial handler for the key instruction. When a key instruction
  * is received, this handler will be called. The client's key handler will
  * be invoked if defined.
  */
-int __guac_handle_key(guac_client* client, guac_instruction* instruction);
+guac_status __guac_handle_key(guac_client* client, guac_instruction* instruction);
 
 /**
  * Internal initial handler for the clipboard instruction. When a clipboard instruction
  * is received, this handler will be called. The client's clipboard handler will
  * be invoked if defined.
  */
-int __guac_handle_clipboard(guac_client* client, guac_instruction* instruction);
+guac_status __guac_handle_clipboard(guac_client* client, guac_instruction* instruction);
 
 /**
  * Internal initial handler for the disconnect instruction. When a disconnect instruction
  * is received, this handler will be called. Disconnect instructions are automatically
  * handled, thus there is no client handler for disconnect instruction.
  */
-int __guac_handle_disconnect(guac_client* client, guac_instruction* instruction);
+guac_status __guac_handle_disconnect(guac_client* client, guac_instruction* instruction);
 
 /**
  * Instruction handler mapping table. This is a NULL-terminated array of
diff --git a/libguac/include/client.h b/libguac/include/client.h
index 3483ce01..3c3e5387 100644
--- a/libguac/include/client.h
+++ b/libguac/include/client.h
@@ -312,9 +312,10 @@ guac_client* guac_get_client(int client_fd);
  * Enter the main network message handling loop for the given client.
  *
  * @param client The proxy client to start handling messages of/for.
- * @return Zero if the client successfully started, non-zero if an error
- *         occurs during startup. Note that this function will still return
- *         zero if an error occurs while the client is running.
+ * @return GUAC_STATUS_SUCCESS if the client successfully started, or any
+ *         other status code if an error occurs during startup. Note that
+ *         this function will still return GUAC_STATUS_SUCCESS
+ *         if an error occurs while the client is running.
  */
 guac_status guac_start_client(guac_client* client);
 
@@ -323,7 +324,7 @@ guac_status guac_start_client(guac_client* client);
  *
  * @param client The proxy client to free all reasources of.
  */
-guac_status guac_free_client(guac_client* client);
+void guac_free_client(guac_client* client);
 
 /**
  * Call the appropriate handler defined by the given client for the given
@@ -334,6 +335,9 @@ guac_status guac_free_client(guac_client* client);
  * @param client The proxy client whose handlers should be called.
  * @param instruction The instruction to pass to the proxy client via the
  *                    appropriate handler.
+ * @return GUAC_STATUS_SUCCESS if no handler was defined or if the handler
+ *         was called successfully, or any other status code if an error
+ *         occurs while calling the defined handler.
  */
 guac_status guac_client_handle_instruction(guac_client* client, guac_instruction* instruction);
 
@@ -344,7 +348,7 @@ guac_status guac_client_handle_instruction(guac_client* client, guac_instruction
  *
  * @param client The proxy client to stop.
  */
-guac_status guac_client_stop(guac_client* client);
+void guac_client_stop(guac_client* client);
 
 /**
  * Allocates a new buffer (invisible layer). An arbitrary index is
@@ -372,7 +376,7 @@ guac_layer* guac_client_alloc_layer(guac_client* client, int index);
  * @param client The proxy client to return the buffer to.
  * @param layer The buffer to return to the pool of available buffers.
  */
-guac_status guac_client_free_buffer(guac_client* client, guac_layer* layer);
+void guac_client_free_buffer(guac_client* client, guac_layer* layer);
 
 /**
  * The default Guacamole client layer, layer 0.
diff --git a/libguac/include/error.h b/libguac/include/error.h
index 06da4a8f..2b897339 100644
--- a/libguac/include/error.h
+++ b/libguac/include/error.h
@@ -67,6 +67,12 @@ typedef enum guac_status {
      */
     GUAC_STATUS_NO_INPUT,
 
+    /**
+     * No data could be read from an input stream, but data may be available
+     * if the operation is retried.
+     */
+    GUAC_STATUS_INPUT_UNAVAILABLE,
+
     /**
      * A timeout occurred while reading from the input stream associated
      * with the operation.
diff --git a/libguac/include/guacio.h b/libguac/include/guacio.h
index f0ee209d..c5ba5afb 100644
--- a/libguac/include/guacio.h
+++ b/libguac/include/guacio.h
@@ -151,7 +151,7 @@ int64_t guac_parse_int(const char* str);
  * @param i The unsigned int to write.
  * @return Zero on success, or non-zero if an error occurs while writing.
  */
-ssize_t guac_write_int(GUACIO* io, int64_t i);
+guac_status guac_write_int(GUACIO* io, int64_t i);
 
 /**
  * Writes the given string to the given GUACIO object. The data
@@ -164,7 +164,7 @@ ssize_t guac_write_int(GUACIO* io, int64_t i);
  * @param str The string to write.
  * @return Zero on success, or non-zero if an error occurs while writing.
 */
-ssize_t guac_write_string(GUACIO* io, const char* str);
+guac_status guac_write_string(GUACIO* io, const char* str);
 
 /**
  * Writes the given binary data to the given GUACIO object as base64-encoded
@@ -179,7 +179,7 @@ ssize_t guac_write_string(GUACIO* io, const char* str);
  * @param count The number of bytes to write.
  * @return Zero on success, or non-zero if an error occurs while writing.
  */
-ssize_t guac_write_base64(GUACIO* io, const void* buf, size_t count);
+guac_status guac_write_base64(GUACIO* io, const void* buf, size_t count);
 
 /**
  * Flushes the base64 buffer, writing padding characters as necessary.
@@ -187,7 +187,7 @@ ssize_t guac_write_base64(GUACIO* io, const void* buf, size_t count);
  * @param io The GUACIO object to flush
  * @return Zero on success, or non-zero if an error occurs during flush.
  */
-ssize_t guac_flush_base64(GUACIO* io);
+guac_status guac_flush_base64(GUACIO* io);
 
 /**
  * Flushes the write buffer.
@@ -195,7 +195,7 @@ ssize_t guac_flush_base64(GUACIO* io);
  * @param io The GUACIO object to flush
  * @return Zero on success, or non-zero if an error occurs during flush.
  */
-ssize_t guac_flush(GUACIO* io);
+guac_status guac_flush(GUACIO* io);
 
 
 /**
@@ -208,7 +208,7 @@ ssize_t guac_flush(GUACIO* io);
  * @return Positive on success, zero if the timeout elapsed and no data is
  *         available, negative on error.
  */
-int guac_select(GUACIO* io, int usec_timeout);
+guac_status guac_select(GUACIO* io, int usec_timeout);
 
 /**
  * Frees resources allocated to the given GUACIO object. Note that this
diff --git a/libguac/include/protocol.h b/libguac/include/protocol.h
index 5f73191f..8ae52846 100644
--- a/libguac/include/protocol.h
+++ b/libguac/include/protocol.h
@@ -176,18 +176,18 @@ void guac_free_instruction(guac_instruction* instruction);
  *
  * @param io The GUACIO connection to use.
  * @param args The NULL-terminated array of argument names (strings).
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_args(GUACIO* io, const char** name);
+guac_status guac_send_args(GUACIO* io, const char** name);
 
 /**
  * Sends a name instruction over the given GUACIO connection.
  *
  * @param io The GUACIO connection to use.
  * @param name The name to send within the name instruction.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_name(GUACIO* io, const char* name);
+guac_status guac_send_name(GUACIO* io, const char* name);
 
 /**
  * Sends a sync instruction over the given GUACIO connection. The
@@ -195,27 +195,27 @@ int guac_send_name(GUACIO* io, const char* name);
  *
  * @param io The GUACIO connection to use.
  * @param timestamp The current timestamp (in milliseconds).
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_sync(GUACIO* io, guac_timestamp timestamp);
+guac_status guac_send_sync(GUACIO* io, guac_timestamp timestamp);
 
 /**
  * Sends an error instruction over the given GUACIO connection.
  *
  * @param io The GUACIO connection to use.
  * @param error The description associated with the error.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_error(GUACIO* io, const char* error);
+guac_status guac_send_error(GUACIO* io, const char* error);
 
 /**
  * Sends a clipboard instruction over the given GUACIO connection.
  *
  * @param io The GUACIO connection to use.
  * @param data The clipboard data to send.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_clipboard(GUACIO* io, const char* data);
+guac_status guac_send_clipboard(GUACIO* io, const char* data);
 
 /**
  * Sends a size instruction over the given GUACIO connection.
@@ -223,9 +223,9 @@ int guac_send_clipboard(GUACIO* io, const char* data);
  * @param io The GUACIO connection to use.
  * @param w The width of the display.
  * @param h The height of the display.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_size(GUACIO* io, int w, int h);
+guac_status guac_send_size(GUACIO* io, int w, int h);
 
 /**
  * Sends a copy instruction over the given GUACIO connection.
@@ -242,9 +242,9 @@ int guac_send_size(GUACIO* io, int w, int h);
  *             should be copied.
  * @param dsty The Y coordinate of the destination, where the source rectangle
  *             should be copied.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_copy(GUACIO* io, 
+guac_status guac_send_copy(GUACIO* io, 
         const guac_layer* srcl, int srcx, int srcy, int w, int h,
         guac_composite_mode mode, const guac_layer* dstl, int dstx, int dsty);
 
@@ -262,9 +262,9 @@ int guac_send_copy(GUACIO* io,
  * @param g The green component of the color of the rectangle.
  * @param b The blue component of the color of the rectangle.
  * @param a The alpha (transparency) component of the color of the rectangle.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_rect(GUACIO* io,
+guac_status guac_send_rect(GUACIO* io,
         guac_composite_mode mode, const guac_layer* layer,
         int x, int y, int width, int height,
         int r, int g, int b, int a);
@@ -278,9 +278,9 @@ int guac_send_rect(GUACIO* io,
  * @param y The Y coordinate of the clipping rectangle.
  * @param width The width of the clipping rectangle.
  * @param height The height of the clipping rectangle.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_clip(GUACIO* io, const guac_layer* layer,
+guac_status guac_send_clip(GUACIO* io, const guac_layer* layer,
         int x, int y, int width, int height);
 
 /**
@@ -293,9 +293,9 @@ int guac_send_clip(GUACIO* io, const guac_layer* layer,
  * @param x The destination X coordinate.
  * @param y The destination Y coordinate.
  * @param surface A cairo surface containing the image data to send.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_png(GUACIO* io, guac_composite_mode mode,
+guac_status guac_send_png(GUACIO* io, guac_composite_mode mode,
         const guac_layer* layer, int x, int y, cairo_surface_t* surface);
 
 /**
@@ -306,19 +306,20 @@ int guac_send_png(GUACIO* io, guac_composite_mode mode,
  * @param x The X coordinate of the cursor hotspot.
  * @param y The Y coordinate of the cursor hotspot.
  * @param surface A cairo surface containing the image data to send.
- * @return Zero on success, non-zero on error.
+ * @return GUAC_STATUS_SUCCESS on success, any other status code on error.
  */
-int guac_send_cursor(GUACIO* io, int x, int y, cairo_surface_t* surface);
+guac_status guac_send_cursor(GUACIO* io, int x, int y, cairo_surface_t* surface);
 
 /**
  * Returns whether new instruction data is available on the given GUACIO
  * connection for parsing.
  *
  * @param io The GUACIO connection to use.
- * @return A positive value if data is available, negative on error, or
- *         zero if no data is currently available.
+ * @return GUAC_STATUS_SUCCESS if data is available,
+ *         GUAC_STATUS_NO_INPUT if no data is currently available,
+ *         or any other status code on error.
  */
-int guac_instructions_waiting(GUACIO* io);
+guac_status guac_instructions_waiting(GUACIO* io);
 
 /**
  * Reads a single instruction from the given GUACIO connection.
@@ -327,13 +328,13 @@ int guac_instructions_waiting(GUACIO* io);
  * @param parsed_instruction A pointer to a guac_instruction structure which
  *                           will be populated with data read from the given
  *                           GUACIO connection.
- * @return A positive value if data was successfully read, negative on
- *         error, or zero if the instruction could not be read completely
- *         because GUAC_TIMEOUT elapsed, in which case subsequent calls to
- *         guac_read_instruction() will return the parsed instruction once
- *         enough data is available.
+ * @return GUAC_STATUS_SUCCESS if data was successfully read, 
+ *         GUAC_STATUS_INPUT_UNAVAILABLE if the instruction could not be read
+ *         completely because GUAC_TIMEOUT elapsed, in which case subsequent
+ *         calls to guac_read_instruction() will return the parsed instruction
+ *         once enough data is available, or any other status code on error.
  */
-int guac_read_instruction(GUACIO* io, guac_instruction* parsed_instruction);
+guac_status guac_read_instruction(GUACIO* io, guac_instruction* parsed_instruction);
 
 guac_timestamp guac_current_timestamp();
 void guac_sleep(int millis);
diff --git a/libguac/src/client.c b/libguac/src/client.c
index a1cafa18..ba5a2d4d 100644
--- a/libguac/src/client.c
+++ b/libguac/src/client.c
@@ -161,26 +161,22 @@ guac_client* guac_get_client(int client_fd) {
 
         /* Wait for data until timeout */
         result = guac_instructions_waiting(io);
-        if (result == 0) {
+        if (result == GUAC_STATUS_TIMEOUT) {
             guac_send_error(io, "Select timeout.");
             guac_close(io);
             return NULL;
         }
 
         /* If error occurs while waiting, exit with failure */
-        if (result < 0) {
+        if (result != GUAC_STATUS_SUCCESS) {
             guac_close(io);
             return NULL;
         }
 
         result = guac_read_instruction(io, &instruction);
-        if (result < 0) {
-            guac_close(io);
-            return NULL;            
-        }
 
         /* Select instruction read */
-        if (result > 0) {
+        if (result == GUAC_STATUS_SUCCESS) {
 
             if (strcmp(instruction.opcode, "select") == 0) {
 
@@ -247,6 +243,12 @@ guac_client* guac_get_client(int client_fd) {
             guac_free_instruction_data(&instruction);
         }
 
+        /* Give up on any legitimate error */
+        else if (result != GUAC_STATUS_INPUT_UNAVAILABLE) {
+            guac_close(io);
+            return NULL;            
+        }
+
     }
 
     /* Wait for connect instruction */
diff --git a/libguac/src/error.c b/libguac/src/error.c
index 6b66b592..310a7377 100644
--- a/libguac/src/error.c
+++ b/libguac/src/error.c
@@ -40,14 +40,15 @@
 
 /* Error strings */
 
-const char* __GUAC_STATUS_SUCCESS_STR        = "Success";
-const char* __GUAC_STATUS_NO_MEMORY_STR      = "Insufficient memory";
-const char* __GUAC_STATUS_NO_INPUT_STR       = "End of input stream";
-const char* __GUAC_STATUS_INPUT_TIMEOUT_STR  = "Read timeout";
-const char* __GUAC_STATUS_OUTPUT_ERROR_STR   = "Output error";
-const char* __GUAC_STATUS_BAD_ARGUMENT_STR   = "Invalid argument";
-const char* __GUAC_STATUS_BAD_STATE_STR      = "Illegal state";
-const char* __GUAC_STATUS_INVALID_STATUS_STR = "UNKNOWN STATUS CODE";
+const char* __GUAC_STATUS_SUCCESS_STR            = "Success";
+const char* __GUAC_STATUS_NO_MEMORY_STR          = "Insufficient memory";
+const char* __GUAC_STATUS_NO_INPUT_STR           = "End of input stream";
+const char* __GUAC_STATUS_INPUT_UNAVAILABLE_STR  = "Input unavailable";
+const char* __GUAC_STATUS_INPUT_TIMEOUT_STR      = "Read timeout";
+const char* __GUAC_STATUS_OUTPUT_ERROR_STR       = "Output error";
+const char* __GUAC_STATUS_BAD_ARGUMENT_STR       = "Invalid argument";
+const char* __GUAC_STATUS_BAD_STATE_STR          = "Illegal state";
+const char* __GUAC_STATUS_INVALID_STATUS_STR     = "UNKNOWN STATUS CODE";
 
 
 const char* guac_status_string(guac_status_t status) {
@@ -66,6 +67,10 @@ const char* guac_status_string(guac_status_t status) {
 		case GUAC_STATUS_NO_INPUT:
             return __GUAC_STATUS_NO_INPUT_STR;
 
+        /* Input unavailable */
+		case GUAC_STATUS_INPUT_UNAVAILABLE:
+            return __GUAC_STATUS_INPUT_UNAVAILABLE_STR;
+
         /* Input timeout */
 		case GUAC_STATUS_INPUT_TIMEOUT:
             return __GUAC_STATUS_INPUT_TIMEOUT_STR;