diff --git a/client/X11/xf_event.c b/client/X11/xf_event.c
index b5b2b71b5..5f13d503d 100644
--- a/client/X11/xf_event.c
+++ b/client/X11/xf_event.c
@@ -101,7 +101,7 @@ BOOL xf_event_action_script_init(xfContext* xfc)
 
 	actionScript = popen(command, "r");
 
-	if (actionScript <= 0)
+	if (!actionScript)
 		return FALSE;
 
 	while (fgets(buffer, sizeof(buffer), actionScript))
@@ -170,7 +170,7 @@ static BOOL xf_event_execute_action_script(xfContext* xfc, XEvent* event)
 
 	actionScript = popen(command, "r");
 
-	if (actionScript < 0)
+	if (!actionScript)
 		return FALSE;
 
 	while (fgets(buffer, sizeof(buffer), actionScript))
diff --git a/client/X11/xf_keyboard.c b/client/X11/xf_keyboard.c
index 963055639..a85186f8a 100644
--- a/client/X11/xf_keyboard.c
+++ b/client/X11/xf_keyboard.c
@@ -72,7 +72,7 @@ BOOL xf_keyboard_action_script_init(xfContext* xfc)
 
 	keyScript = popen(command, "r");
 
-	if (keyScript < 0)
+	if (!keyScript)
 	{
 		free(xfc->actionScript);
 		xfc->actionScript = NULL;
@@ -414,7 +414,7 @@ int xf_keyboard_execute_action_script(xfContext* xfc, XF_MODIFIER_KEYS* mod, Key
 
 	keyScript = popen(command, "r");
 
-	if (keyScript < 0)
+	if (!keyScript)
 		return -1;
 
 	while (fgets(buffer, sizeof(buffer), keyScript) != NULL)
diff --git a/libfreerdp/locale/keyboard_sun.c b/libfreerdp/locale/keyboard_sun.c
index 5f8b62e17..111abf7bd 100644
--- a/libfreerdp/locale/keyboard_sun.c
+++ b/libfreerdp/locale/keyboard_sun.c
@@ -227,7 +227,7 @@ int freerdp_get_solaris_keyboard_layout_and_type(int* type, int* layout)
 
 	kbd = popen("kbd -t -l", "r");
 
-	if (kbd < 0)
+	if (!kbd)
 		return -1;
 
 	while (fgets(buffer, sizeof(buffer), kbd) != NULL)
diff --git a/libfreerdp/locale/keyboard_x11.c b/libfreerdp/locale/keyboard_x11.c
index 387644d1b..e9ca41f2a 100644
--- a/libfreerdp/locale/keyboard_x11.c
+++ b/libfreerdp/locale/keyboard_x11.c
@@ -48,7 +48,8 @@ int freerdp_detect_keyboard_layout_from_xkb(DWORD* keyboardLayoutId)
 
 	/* We start by looking for _XKB_RULES_NAMES_BACKUP which appears to be used by libxklavier */
 
-        xprop = popen("xprop -root _XKB_RULES_NAMES_BACKUP", "r");
+    if (!(xprop = popen("xprop -root _XKB_RULES_NAMES_BACKUP", "r")))
+		return 0;
 
 	/* Sample output for "Canadian Multilingual Standard"
 	 *
@@ -100,7 +101,8 @@ int freerdp_detect_keyboard_layout_from_xkb(DWORD* keyboardLayoutId)
 
 	/* Check _XKB_RULES_NAMES if _XKB_RULES_NAMES_BACKUP fails */
 
-	xprop = popen("xprop -root _XKB_RULES_NAMES", "r");
+	if (!(xprop = popen("xprop -root _XKB_RULES_NAMES", "r")))
+		return 0;
 
 	while (fgets(buffer, sizeof(buffer), xprop) != NULL)
 	{
@@ -157,6 +159,9 @@ char* freerdp_detect_keymap_from_xkb()
 	/* this tells us about the current XKB configuration, if XKB is available */
 	setxkbmap = popen("setxkbmap -print", "r");
 
+	if (!setxkbmap)
+		return NULL;
+
 	while (fgets(buffer, sizeof(buffer), setxkbmap) != NULL)
 	{
 		/* the line with xkb_keycodes is what interests us */