diff --git a/src/util-base64.c b/src/util-base64.c
index f4b508a019..45fdc01ab4 100644
--- a/src/util-base64.c
+++ b/src/util-base64.c
@@ -83,10 +83,13 @@ static inline void DecodeBase64Block(uint8_t ascii[ASCII_BLOCK], uint8_t b64[B64
  * \param dest The destination byte buffer
  * \param src The source string
  * \param len The length of the source string
+ * \param strict If set file on invalid byte, otherwise return what has been
+ *    decoded.
  *
  * \return Number of bytes decoded, or 0 if no data is decoded or it fails
  */
-uint32_t DecodeBase64(uint8_t *dest, const uint8_t *src, uint32_t len) {
+uint32_t DecodeBase64(uint8_t *dest, const uint8_t *src, uint32_t len,
+    int strict) {
 
     int val;
     uint32_t padding = 0, numDecoded = 0, bbidx = 0, valid = 1, i;
@@ -103,7 +106,9 @@ uint32_t DecodeBase64(uint8_t *dest, const uint8_t *src, uint32_t len) {
             /* Invalid character found, so decoding fails */
             if (src[i] != '=') {
                 valid = 0;
-                numDecoded = 0;
+                if (strict) {
+                    numDecoded = 0;
+                }
                 break;
             }
             padding++;
diff --git a/src/util-base64.h b/src/util-base64.h
index fb1a90a3b5..7c8bed6262 100644
--- a/src/util-base64.h
+++ b/src/util-base64.h
@@ -49,6 +49,7 @@
 #define B64_BLOCK           4
 
 /* Function prototypes */
-uint32_t DecodeBase64(uint8_t *dest, const uint8_t *src, uint32_t len);
+uint32_t DecodeBase64(uint8_t *dest, const uint8_t *src, uint32_t len,
+    int strict);
 
 #endif
diff --git a/src/util-decode-mime.c b/src/util-decode-mime.c
index 51d1468e55..ded4cd6044 100644
--- a/src/util-decode-mime.c
+++ b/src/util-decode-mime.c
@@ -1227,7 +1227,7 @@ static uint8_t ProcessBase64Remainder(const uint8_t *buf, uint32_t len,
     /* Only decode if divisible by 4 */
     if (state->bvr_len == B64_BLOCK || force) {
         remdec = DecodeBase64(state->data_chunk + state->data_chunk_len,
-                              state->bvremain, state->bvr_len);
+                              state->bvremain, state->bvr_len, 1);
         if (remdec > 0) {
 
             /* Track decoded length */
@@ -1329,7 +1329,7 @@ static int ProcessBase64BodyLine(const uint8_t *buf, uint32_t len,
             SCLogDebug("Decoding: %u", len - rem1 - rem2);
 
             numDecoded = DecodeBase64(state->data_chunk + state->data_chunk_len,
-                    buf + offset, tobuf);
+                    buf + offset, tobuf, 1);
             if (numDecoded > 0) {
 
                 /* Track decoded length */
@@ -2888,7 +2888,7 @@ static int MimeBase64DecodeTest01(void)
     if (dst == NULL)
         return 0;
 
-    ret = DecodeBase64(dst, (const uint8_t *)base64msg, strlen(base64msg));
+    ret = DecodeBase64(dst, (const uint8_t *)base64msg, strlen(base64msg), 1);
 
     if (memcmp(dst, msg, strlen(msg)) == 0) {
         ret = 0;