diff --git a/lib/source-map-consumer.js b/lib/source-map-consumer.js
index 17ef92b1..8fc66f11 100644
--- a/lib/source-map-consumer.js
+++ b/lib/source-map-consumer.js
@@ -939,14 +939,26 @@ class IndexedSourceMapConsumer extends SourceMapConsumer {
   }
 
   allGeneratedPositionsFor(aArgs) {
-    const index = this._findSectionIndex(util.getArg(aArgs, "source"));
-    const section = index >= 0 ? this._sections[index] : null;
-    const nextSection =
-      index >= 0 && index + 1 < this._sections.length
-        ? this._sections[index + 1]
-        : null;
+    const source = util.getArg(aArgs, "source");
+    let positions = [];
+
+    // The same original source can appear in more than one section, so
+    // collect the positions from every section that contains it.
+    for (let i = 0; i < this._sections.length; i++) {
+      if (this._sections[i].consumer._findSourceIndex(source) !== -1) {
+        positions = positions.concat(
+          this._sectionGeneratedPositionsFor(i, aArgs)
+        );
+      }
+    }
 
-    if (!section) return [];
+    return positions;
+  }
+
+  _sectionGeneratedPositionsFor(index, aArgs) {
+    const section = this._sections[index];
+    const nextSection =
+      index + 1 < this._sections.length ? this._sections[index + 1] : null;
 
     return section.consumer
       .allGeneratedPositionsFor(aArgs)
diff --git a/test/test-source-map-consumer.js b/test/test-source-map-consumer.js
index 8cf50988..a1e2cdff 100644
--- a/test/test-source-map-consumer.js
+++ b/test/test-source-map-consumer.js
@@ -1490,6 +1490,56 @@ exports["test allGeneratedPositionsFor for index map"] = async function (
   map.destroy();
 };
 
+exports[
+  "test allGeneratedPositionsFor for index map with a source in several sections"
+] = async function (assert) {
+  const map = await new SourceMapConsumer({
+    version: 3,
+    file: "min.js",
+    sections: [
+      {
+        offset: { line: 0, column: 0 },
+        map: {
+          version: 3,
+          sources: ["shared.js"],
+          names: [],
+          mappings: "AAAA",
+        },
+      },
+      {
+        offset: { line: 2, column: 4 },
+        map: {
+          version: 3,
+          sources: ["shared.js"],
+          names: [],
+          mappings: "AAAA",
+        },
+      },
+    ],
+  });
+
+  const mappings = map.allGeneratedPositionsFor({
+    line: 1,
+    column: 0,
+    source: "shared.js",
+  });
+
+  assert.deepEqual(mappings, [
+    {
+      line: 1,
+      column: 0,
+      lastColumn: null,
+    },
+    {
+      line: 3,
+      column: 4,
+      lastColumn: null,
+    },
+  ]);
+
+  map.destroy();
+};
+
 exports["test computeColumnSpans"] = async function (assert) {
   let map = new SourceMapGenerator({
     file: "generated.js",