diff --git a/crates/owlry-core/src/filter.rs b/crates/owlry-core/src/filter.rs
index f90ce8b..0ec34bd 100644
--- a/crates/owlry-core/src/filter.rs
+++ b/crates/owlry-core/src/filter.rs
@@ -360,6 +360,28 @@ impl ProviderFilter {
             }
         }
 
+        // Dynamic plugin prefix fallback: ":word " or ":word" where word is unknown
+        // Maps to Plugin(word) so user plugins with custom prefixes work
+        if let Some(rest) = trimmed.strip_prefix(':') {
+            if let Some(space_idx) = rest.find(' ') {
+                let prefix_word = &rest[..space_idx];
+                if !prefix_word.is_empty() && prefix_word.chars().all(|c| c.is_alphanumeric() || c == '-' || c == '_') {
+                    return ParsedQuery {
+                        prefix: Some(ProviderType::Plugin(prefix_word.to_string())),
+                        tag_filter: None,
+                        query: rest[space_idx + 1..].to_string(),
+                    };
+                }
+            } else if !rest.is_empty() && rest.chars().all(|c| c.is_alphanumeric() || c == '-' || c == '_') {
+                // Partial prefix (no space yet)
+                return ParsedQuery {
+                    prefix: Some(ProviderType::Plugin(rest.to_string())),
+                    tag_filter: None,
+                    query: String::new(),
+                };
+            }
+        }
+
         let result = ParsedQuery {
             prefix: None,
             tag_filter: None,