diff --git a/niworkflows/data/nipreps.json b/niworkflows/data/nipreps.json
index 8e1449d903c..d704d783b58 100644
--- a/niworkflows/data/nipreps.json
+++ b/niworkflows/data/nipreps.json
@@ -71,7 +71,7 @@
     },
     {
       "name": "space",
-      "pattern": "[_/\\\\]+space-([a-zA-Z0-9+\\+]+)"
+      "pattern": "[_/\\\\]+space-([a-zA-Z0-9+]+)"
     },
     {
       "name": "suffix",
@@ -115,11 +115,11 @@
     },
     {
       "name": "from",
-      "pattern": "(?:^|_)from-([a-zA-Z0-9+\\+]+).*xfm"
+      "pattern": "(?:^|_)from-([a-zA-Z0-9+]+).*xfm"
     },
     {
       "name": "to",
-      "pattern": "(?:^|_)to-([a-zA-Z0-9+\\+]+).*xfm"
+      "pattern": "(?:^|_)to-([a-zA-Z0-9+]+).*xfm"
     },
     {
       "name": "mode",