diff --git a/common.c b/common.c
index 0b7a26aed..16e8b09b9 100644
--- a/common.c
+++ b/common.c
@@ -704,7 +704,7 @@ wchar_t *escape( const wchar_t *in,
 	if( !in )
 	{
 		debug( 0, L"%s called with null input", __func__ );
-		exit(1);
+		FATAL_EXIT();
 	}
 	
 	out = malloc( sizeof(wchar_t)*(wcslen(in)*4 + 1));
diff --git a/common.h b/common.h
index f5603d418..f362f7f2c 100644
--- a/common.h
+++ b/common.h
@@ -91,9 +91,9 @@ extern wchar_t *program_name;
 	}
 
 /**
-   Cause fish to crash. If supported, print a backtrace first.
+   Pause for input, then exit the program. If supported, print a backtrace first.
 */
-#define CRASH()									\
+#define FATAL_EXIT()							\
 	{											\
 		char c;									\
 		show_stackframe();						\
@@ -111,7 +111,7 @@ extern wchar_t *program_name;
 				  L"fish: Out of memory on line %d of file %s, shutting down fish\n", \
 				  __LINE__,												\
 				  __FILE__ );											\
-		CRASH();														\
+		FATAL_EXIT();														\
 	}
 
 /**
diff --git a/exec.c b/exec.c
index f99cf6790..1e31699fc 100644
--- a/exec.c
+++ b/exec.c
@@ -220,7 +220,7 @@ void free_fd( io_data_t *io, int fd )
 								   FD_ERROR,
 								   fd );							
 							wperror( L"dup" );
-							exit(1);
+							FATAL_EXIT();
 						}
 					}
 					else
@@ -515,7 +515,7 @@ static void launch_process( process_t *p )
 	errno = err;
 	
 	wperror( L"execve" );
-	exit(1);
+	FATAL_EXIT();
 }
 
 
@@ -761,7 +761,7 @@ static pid_t exec_fork()
 	
 	debug( 0, FORK_ERROR );
 	wperror (L"fork");
-	exit( 1 );
+	FATAL_EXIT();
 }
 
 
diff --git a/parser.c b/parser.c
index 41b0bc8cf..8a8525870 100644
--- a/parser.c
+++ b/parser.c
@@ -2588,7 +2588,7 @@ int eval( const wchar_t *cmd, io_data_t *io, int block_type )
 			debug( 0,
 				   _(L"End of block mismatch. Program terminating.") );
 			bugreport();
-			exit(1);
+			FATAL_EXIT();
 			break;
 		}
 
diff --git a/signal.c b/signal.c
index 40e23f79a..b5271e0a1 100644
--- a/signal.c
+++ b/signal.c
@@ -557,7 +557,7 @@ void signal_set_handlers()
 		if( sigaction( SIGINT, &act, 0) )
 		{
 			wperror( L"sigaction" );
-			exit(1);
+			FATAL_EXIT();
 		}
 
 		act.sa_sigaction = &handle_chld;
@@ -565,7 +565,7 @@ void signal_set_handlers()
 		if( sigaction( SIGCHLD, &act, 0) )
 		{
 			wperror( L"sigaction" );
-			exit(1);
+			FATAL_EXIT();
 		}
 		
 #ifdef SIGWINCH
@@ -574,7 +574,7 @@ void signal_set_handlers()
 		if( sigaction( SIGWINCH, &act, 0 ) )
 		{
 			wperror( L"sigaction" );
-			exit(1);
+			FATAL_EXIT();
 		}
 #endif
 
@@ -583,7 +583,7 @@ void signal_set_handlers()
 		if( sigaction( SIGHUP, &act, 0 ) )
 		{
 			wperror( L"sigaction" );
-			exit(1);
+			FATAL_EXIT();
 		}
 
 	}
@@ -661,6 +661,13 @@ void signal_unblock()
 
 	block_count--;
 
+	if( block_count < 0 )
+	{
+		debug( 0, _( L"Signal block mismatch" ) );
+		bugreport();
+		FATAL_EXIT();
+	}
+	
 	if( !block_count )
 	{
 		sigfillset( &chldset );