diff --git a/tests/Makefile b/tests/Makefile
index 82eb67c447..4c21a6a5a4 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -116,7 +116,7 @@ fate: $(FATE)
 
 $(FATE): avconv$(EXESUF) $(FATE_UTILS:%=tests/%$(HOSTEXESUF))
 	@echo "TEST    $(@:fate-%=%)"
-	$(Q)$(SRC_PATH)/tests/fate-run.sh $@ "$(SAMPLES)" "$(TARGET_EXEC)" "$(TARGET_PATH)" '$(CMD)' '$(CMP)' '$(REF)' '$(FUZZ)' '$(THREADS)' '$(THREAD_TYPE)' '$(CPUFLAGS)' '$(CMP_SHIFT)' '$(CMP_TARGET)'
+	$(Q)$(SRC_PATH)/tests/fate-run.sh $@ "$(SAMPLES)" "$(TARGET_EXEC)" "$(TARGET_PATH)" '$(CMD)' '$(CMP)' '$(REF)' '$(FUZZ)' '$(THREADS)' '$(THREAD_TYPE)' '$(CPUFLAGS)' '$(CMP_SHIFT)' '$(CMP_TARGET)' '$(SIZE_TOLERANCE)'
 
 fate-list:
 	@printf '%s\n' $(sort $(FATE))
diff --git a/tests/fate-run.sh b/tests/fate-run.sh
index 07065c3f30..40a4fe2f6d 100755
--- a/tests/fate-run.sh
+++ b/tests/fate-run.sh
@@ -20,6 +20,7 @@ thread_type=${10:-frame+slice}
 cpuflags=${11:-all}
 cmp_shift=${12:-0}
 cmp_target=${13:-0}
+size_tolerance=${14:-0}
 
 outdir="tests/data/fate"
 outfile="${outdir}/${test}"
@@ -40,7 +41,8 @@ do_tiny_psnr(){
     size1=$(expr "$psnr" : '.*bytes: *\([0-9]*\)')
     size2=$(expr "$psnr" : '.*bytes:[ 0-9]*/ *\([0-9]*\)')
     val_cmp=$(compare $val $cmp_target $fuzz)
-    if [ "$val_cmp" != 0 ] || [ $size1 != $size2 ]; then
+    size_cmp=$(compare $size1 $size2 $size_tolerance)
+    if [ "$val_cmp" != 0 ] || [ "$size_cmp" != 0 ]; then
         echo "$psnr"
         return 1
     fi