diff --git a/src/output/output_csv.c b/src/output/output_csv.c
index 52ee7dca..94699444 100644
--- a/src/output/output_csv.c
+++ b/src/output/output_csv.c
@@ -84,8 +84,8 @@ typedef char *(*string_function_t)(char *, recordHandle_t *);
     } while (0)
 
 #define STREAMBUFFSIZE 4096
-#define STREAMLEN(ptr)  \
-    (ptr - streamBuff); \
+#define STREAMLEN(ptr)                                \
+    ((ptrdiff_t)STREAMBUFFSIZE - (ptr - streamBuff)); \
     assert((ptr - streamBuff) < STREAMBUFFSIZE)
 static char *streamBuff = NULL;
 
diff --git a/src/output/output_json.c b/src/output/output_json.c
index 98774b26..2e105ed7 100644
--- a/src/output/output_json.c
+++ b/src/output/output_json.c
@@ -115,8 +115,8 @@ static uint32_t recordCount = 0;
     } while (0)
 
 #define STREAMBUFFSIZE 4096
-#define STREAMLEN(ptr)  \
-    (ptr - streamBuff); \
+#define STREAMLEN(ptr)                                \
+    ((ptrdiff_t)STREAMBUFFSIZE - (ptr - streamBuff)); \
     assert((ptr - streamBuff) < STREAMBUFFSIZE)
 static char *streamBuff = NULL;
 
diff --git a/src/output/output_ndjson.c b/src/output/output_ndjson.c
index 5891df28..362a08a7 100644
--- a/src/output/output_ndjson.c
+++ b/src/output/output_ndjson.c
@@ -103,8 +103,8 @@ static uint32_t recordCount = 0;
     } while (0)
 
 #define STREAMBUFFSIZE 4096
-#define STREAMLEN(ptr)  \
-    (ptr - streamBuff); \
+#define STREAMLEN(ptr)                                \
+    ((ptrdiff_t)STREAMBUFFSIZE - (ptr - streamBuff)); \
     assert((ptr - streamBuff) < STREAMBUFFSIZE)
 static char *streamBuff = NULL;