diff --git a/src/defrag.c b/src/defrag.c
index 74757be063..f230a09cc3 100644
--- a/src/defrag.c
+++ b/src/defrag.c
@@ -225,8 +225,8 @@ DefragContextNew(void)
     SCLogDebug("\tTimeout: %"PRIuMAX, (uintmax_t)dc->timeout);
     SCLogDebug("\tMaximum defrag trackers: %"PRIuMAX, tracker_pool_size);
     SCLogDebug("\tPreallocated defrag trackers: %"PRIuMAX, tracker_pool_size);
-    SCLogDebug("\tMaximum fragments: %ld", frag_pool_size);
-    SCLogDebug("\tPreallocated fragments: %ld", frag_pool_prealloc);
+    SCLogDebug("\tMaximum fragments: %"PRIuMAX, (uintmax_t)frag_pool_size);
+    SCLogDebug("\tPreallocated fragments: %"PRIuMAX, (uintmax_t)frag_pool_prealloc);
 
     return dc;
 }
diff --git a/src/detect-flowvar.c b/src/detect-flowvar.c
index c01ef37019..9379a64a4a 100644
--- a/src/detect-flowvar.c
+++ b/src/detect-flowvar.c
@@ -203,8 +203,8 @@ static int DetectFlowvarSetup (DetectEngineCtx *de_ctx, Signature *s, char *raws
 #ifdef DEBUG
         if (SCLogDebugEnabled()) {
             for (i = 0; i < x; i++) {
-                if (isprint(str[i])) printf("%c", str[i]);
-                else                 printf("\\x%02u", str[i]);
+                if (isprint((unsigned char)str[i])) printf("%c", str[i]);
+                else printf("\\x%02u", str[i]);
             }
             printf("\n");
         }
diff --git a/src/detect-pktvar.c b/src/detect-pktvar.c
index 603b3b018d..e7f12cc2cf 100644
--- a/src/detect-pktvar.c
+++ b/src/detect-pktvar.c
@@ -199,8 +199,8 @@ static int DetectPktvarSetup (DetectEngineCtx *de_ctx, Signature *s, char *rawst
 #ifdef DEBUG
     if (SCLogDebugEnabled()) {
         for (i = 0; i < x; i++) {
-            if (isprint(str[i])) printf("%c", str[i]);
-            else                 printf("\\x%02u", str[i]);
+            if (isprint((unsigned char)str[i])) printf("%c", str[i]);
+            else printf("\\x%02u", str[i]);
         }
         printf("\n");
     }