diff --git a/swh/model/identifiers.py b/swh/model/identifiers.py
--- a/swh/model/identifiers.py
+++ b/swh/model/identifiers.py
@@ -848,14 +848,22 @@
     _metadata = {}
     for part in swhid_parts:
         try:
-            qualifier, val = part.split("=")
+            qualifier, qualifier_value = part.split("=")
             if qualifier not in CONTEXT_QUALIFIERS:
                 error_msg = (
                     f"Invalid SWHID: qualifier must be one "
                     f" of {', '.join(CONTEXT_QUALIFIERS)}"
                 )
                 raise ValidationError(error_msg)
-            _metadata[qualifier] = val
+
+            qualifier_value_stripped = qualifier_value.strip()
+            if qualifier_value_stripped != qualifier_value:
+                error_msg = (
+                    "Invalid SwHID: qualifier value must be free of blank characters "
+                    " before or after its value"
+                )
+                raise ValidationError(error_msg)
+            _metadata[qualifier] = qualifier_value
         except Exception:
             raise ValidationError(
                 "Invalid SWHID: contextual data must be a ;-separated list of "
diff --git a/swh/model/tests/test_identifiers.py b/swh/model/tests/test_identifiers.py
--- a/swh/model/tests/test_identifiers.py
+++ b/swh/model/tests/test_identifiers.py
@@ -1069,6 +1069,10 @@
         "swh:1:dir:0b6959356d30f1a4e9b7f6bca59b9a336464c03d;origin=something;anchor=1;visit=1;pa=/",  # noqa
         # qualifier off: line should be lines
         "swh:1:dir:0b6959356d30f1a4e9b7f6bca59b9a336464c03d;line=10;origin=something;anchor=1;visit=1;path=/",  # noqa
+        # qualifier value is off: it contains space before of after
+        "swh:1:dir:0b6959356d30f1a4e9b7f6bca59b9a336464c03d;origin=  https://some-url",  # noqa
+        "swh:1:dir:0b6959356d30f1a4e9b7f6bca59b9a336464c03d;origin=something;anchor=some-anchor    ",  # noqa
+        "swh:1:dir:0b6959356d30f1a4e9b7f6bca59b9a336464c03d;origin=something;anchor=some-anchor    ;visit=1",  # noqa
     ],
 )
 def test_parse_swhid_parsing_error(invalid_swhid):