diff --git a/src/perl/perl-signals.c b/src/perl/perl-signals.c
index 5ea40d73..792b1746 100644
--- a/src/perl/perl-signals.c
+++ b/src/perl/perl-signals.c
@@ -440,7 +440,7 @@ static void perl_signal_add_full_int(const char *signal, SV *func,
 
         script = perl_script_find_package(perl_get_package());
         g_return_if_fail(script != NULL);
-	g_return_if_fail(script->unloaded);
+	g_return_if_fail(!script->unloaded);
 
 	rec = g_new(PERL_SIGNAL_REC, 1);
         rec->script = script;
diff --git a/src/perl/perl-sources.c b/src/perl/perl-sources.c
index 57fb579d..16260007 100644
--- a/src/perl/perl-sources.c
+++ b/src/perl/perl-sources.c
@@ -107,7 +107,7 @@ int perl_timeout_add(int msecs, SV *func, SV *data, int once)
         pkg = perl_get_package();
 	script = perl_script_find_package(pkg);
         g_return_val_if_fail(script != NULL, -1);
-	g_return_val_if_fail(script->unloaded, -1);
+	g_return_val_if_fail(!script->unloaded, -1);
 
 	rec = g_new0(PERL_SOURCE_REC, 1);
 	perl_source_ref(rec);
@@ -131,7 +131,7 @@ int perl_input_add(int source, int condition, SV *func, SV *data, int once)
         pkg = perl_get_package();
 	script = perl_script_find_package(pkg);
         g_return_val_if_fail(script != NULL, -1);
-	g_return_val_if_fail(script->unloaded, -1);
+	g_return_val_if_fail(!script->unloaded, -1);
 
 	rec = g_new0(PERL_SOURCE_REC, 1);
 	perl_source_ref(rec);