diff --git a/download.go b/download.go
index 2bb57fe2..7bb7099b 100644
--- a/download.go
+++ b/download.go
@@ -67,7 +67,7 @@ func checkTypeAndDimensions(r io.Reader) (imageType, error) {
 	if imgconf.Width > conf.MaxSrcDimension || imgconf.Height > conf.MaxSrcDimension {
 		return UNKNOWN, errors.New("File is too big")
 	}
-	if !imgtypeOk || !vipsTypeSupportedLoad(imgtype) {
+	if !imgtypeOk || !vipsTypeSupportLoad[imgtype] {
 		return UNKNOWN, errors.New("Source image type not supported")
 	}
 
diff --git a/process.go b/process.go
index 5e93fd2e..9b2a6080 100644
--- a/process.go
+++ b/process.go
@@ -78,6 +78,8 @@ type processingOptions struct {
 }
 
 var vipsSupportSmartcrop bool
+var vipsTypeSupportLoad = make(map[imageType]bool)
+var vipsTypeSupportSave = make(map[imageType]bool)
 
 func initVips() {
 	runtime.LockOSThread()
@@ -97,6 +99,29 @@ func initVips() {
 	}
 
 	vipsSupportSmartcrop = C.vips_support_smartcrop() == 1
+
+	if int(C.vips_type_find_load_go(C.JPEG)) != 0 {
+		vipsTypeSupportLoad[JPEG] = true
+	}
+	if int(C.vips_type_find_load_go(C.PNG)) != 0 {
+		vipsTypeSupportLoad[PNG] = true
+	}
+	if int(C.vips_type_find_load_go(C.WEBP)) != 0 {
+		vipsTypeSupportLoad[WEBP] = true
+	}
+	if int(C.vips_type_find_load_go(C.GIF)) != 0 {
+		vipsTypeSupportLoad[GIF] = true
+	}
+
+	if int(C.vips_type_find_save_go(C.JPEG)) != 0 {
+		vipsTypeSupportSave[JPEG] = true
+	}
+	if int(C.vips_type_find_save_go(C.PNG)) != 0 {
+		vipsTypeSupportSave[PNG] = true
+	}
+	if int(C.vips_type_find_save_go(C.WEBP)) != 0 {
+		vipsTypeSupportSave[WEBP] = true
+	}
 }
 
 func randomAccessRequired(po processingOptions) int {
@@ -106,32 +131,6 @@ func randomAccessRequired(po processingOptions) int {
 	return 0
 }
 
-func vipsTypeSupportedLoad(imgtype imageType) bool {
-	switch imgtype {
-	case JPEG:
-		return int(C.vips_type_find_load_go(C.JPEG)) != 0
-	case PNG:
-		return int(C.vips_type_find_load_go(C.PNG)) != 0
-	case WEBP:
-		return int(C.vips_type_find_load_go(C.WEBP)) != 0
-	case GIF:
-		return int(C.vips_type_find_load_go(C.GIF)) != 0
-	}
-	return false
-}
-
-func vipsTypeSupportedSave(imgtype imageType) bool {
-	switch imgtype {
-	case JPEG:
-		return int(C.vips_type_find_save_go(C.JPEG)) != 0
-	case PNG:
-		return int(C.vips_type_find_save_go(C.PNG)) != 0
-	case WEBP:
-		return int(C.vips_type_find_save_go(C.WEBP)) != 0
-	}
-	return false
-}
-
 func round(f float64) int {
 	return int(f + .5)
 }
diff --git a/server.go b/server.go
index f0123946..e8595e8e 100644
--- a/server.go
+++ b/server.go
@@ -77,7 +77,7 @@ func parsePath(r *http.Request) (string, processingOptions, error) {
 		return "", po, fmt.Errorf("Invalid image format: %s", filenameParts[1])
 	}
 
-	if !vipsTypeSupportedSave(po.format) {
+	if !vipsTypeSupportSave[po.format] {
 		return "", po, errors.New("Resulting image type not supported")
 	}