diff --git a/web/ui/module/codemirror-promql/src/complete/hybrid.test.ts b/web/ui/module/codemirror-promql/src/complete/hybrid.test.ts
index 526a5ce4f8..25a2e8fb78 100644
--- a/web/ui/module/codemirror-promql/src/complete/hybrid.test.ts
+++ b/web/ui/module/codemirror-promql/src/complete/hybrid.test.ts
@@ -559,6 +559,18 @@ describe('analyzeCompletion test', () => {
       pos: 28,
       expectedContext: [{ kind: ContextKind.Duration }],
     },
+    {
+      title: 'do not autocomplete duration when unit already present in matrixSelector',
+      expr: 'rate(foo[5m])',
+      pos: 10,
+      expectedContext: [],
+    },
+    {
+      title: 'do not autocomplete duration when multi char unit already present in matrixSelector',
+      expr: 'rate(foo[5ms])',
+      pos: 10,
+      expectedContext: [],
+    },
     {
       title: 'autocomplete duration for a subQuery',
       expr: 'go[5d:5]',
@@ -1229,6 +1241,28 @@ describe('autocomplete promQL test', () => {
         validFor: undefined,
       },
     },
+    {
+      title: 'offline do not autocomplete duration when unit already present in matrixSelector',
+      expr: 'rate(foo[5m])',
+      pos: 10,
+      expectedResult: {
+        options: [],
+        from: 10,
+        to: 10,
+        validFor: /^[a-zA-Z0-9_:]+$/,
+      },
+    },
+    {
+      title: 'offline do not autocomplete duration when multi char unit already present in matrixSelector',
+      expr: 'rate(foo[5ms])',
+      pos: 10,
+      expectedResult: {
+        options: [],
+        from: 10,
+        to: 10,
+        validFor: /^[a-zA-Z0-9_:]+$/,
+      },
+    },
     {
       title: 'offline autocomplete duration for a subQuery',
       expr: 'go[5d:5]',
diff --git a/web/ui/module/codemirror-promql/src/complete/hybrid.ts b/web/ui/module/codemirror-promql/src/complete/hybrid.ts
index 76efc34442..429ac468dd 100644
--- a/web/ui/module/codemirror-promql/src/complete/hybrid.ts
+++ b/web/ui/module/codemirror-promql/src/complete/hybrid.ts
@@ -166,6 +166,25 @@ function arrayToCompletionResult(data: Completion[], from: number, to: number, i
   } as CompletionResult;
 }
 
+const durationUnitLabels = durationTerms
+  .map((term) => term.label)
+  .filter((label): label is string => typeof label === 'string')
+  .sort((a, b) => b.length - a.length);
+
+const durationWithUnitRegexp = new RegExp(`^\\d+(?:${durationUnitLabels.map((label) => escapeRegExp(label)).join('|')})$`);
+
+function escapeRegExp(value: string): string {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+function hasCompleteDurationUnit(state: EditorState, node: SyntaxNode): boolean {
+  if (node.from >= node.to) {
+    return false;
+  }
+  const nodeContent = state.sliceDoc(node.from, node.to);
+  return durationWithUnitRegexp.test(nodeContent);
+}
+
 // computeStartCompleteLabelPositionInLabelMatcherOrInGroupingLabel calculates the start position only when the node is a LabelMatchers or a GroupingLabels
 function computeStartCompleteLabelPositionInLabelMatcherOrInGroupingLabel(node: SyntaxNode, pos: number): number {
   // Here we can have two different situations:
@@ -477,12 +496,18 @@ export function analyzeCompletion(state: EditorState, node: SyntaxNode, pos: num
         //   Duration, Duration, ⚠(NumberLiteral)
         // )
         // So we should continue to autocomplete a duration
-        result.push({ kind: ContextKind.Duration });
+        if (!hasCompleteDurationUnit(state, node)) {
+          result.push({ kind: ContextKind.Duration });
+        }
       } else {
         result.push({ kind: ContextKind.Number });
       }
       break;
     case NumberDurationLiteralInDurationContext:
+      if (!hasCompleteDurationUnit(state, node)) {
+        result.push({ kind: ContextKind.Duration });
+      }
+      break;
     case OffsetExpr:
       result.push({ kind: ContextKind.Duration });
       break;