diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
index 89d306fb94046..c59413abc352d 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
@@ -1548,8 +1548,8 @@ class MemRegionManager {
   ///  a specified FieldDecl.  'superRegion' corresponds to the containing
   ///  memory region (which typically represents the memory representing
   ///  a structure or class).
-  const FieldRegion *getFieldRegion(const FieldDecl *fd,
-                                    const SubRegion* superRegion);
+  const FieldRegion *getFieldRegion(const FieldDecl *FD,
+                                    const SubRegion *SuperRegion);
 
   const FieldRegion *getFieldRegionWithSuper(const FieldRegion *FR,
                                              const SubRegion *superRegion) {
diff --git a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
index 5f271963e3d09..f20e79ae675a4 100644
--- a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -1268,10 +1268,10 @@ const SymbolicRegion *MemRegionManager::getSymbolicHeapRegion(SymbolRef Sym) {
   return getSubRegion<SymbolicRegion>(Sym, getHeapRegion());
 }
 
-const FieldRegion*
-MemRegionManager::getFieldRegion(const FieldDecl *d,
-                                 const SubRegion* superRegion){
-  return getSubRegion<FieldRegion>(d, superRegion);
+const FieldRegion *
+MemRegionManager::getFieldRegion(const FieldDecl *FD,
+                                 const SubRegion *SuperRegion) {
+  return getSubRegion<FieldRegion>(FD->getCanonicalDecl(), SuperRegion);
 }
 
 const ObjCIvarRegion*
@@ -1704,16 +1704,23 @@ static RegionOffset calculateOffset(const MemRegion *R) {
       if (SymbolicOffsetBase)
         continue;
 
-      // Get the field number.
-      unsigned idx = 0;
-      for (RecordDecl::field_iterator FI = RD->field_begin(),
-             FE = RD->field_end(); FI != FE; ++FI, ++idx) {
-        if (FR->getDecl() == *FI)
-          break;
+      assert(FR->getDecl()->getCanonicalDecl() == FR->getDecl());
+      auto MaybeFieldIdx = [FR, RD]() -> std::optional<unsigned> {
+        for (auto [Idx, Field] : llvm::enumerate(RD->fields())) {
+          if (FR->getDecl() == Field->getCanonicalDecl())
+            return Idx;
+        }
+        return std::nullopt;
+      }();
+
+      if (!MaybeFieldIdx.has_value()) {
+        assert(false && "Field not found");
+        goto Finish; // Invalid offset.
       }
+
       const ASTRecordLayout &Layout = R->getContext().getASTRecordLayout(RD);
       // This is offset in bits.
-      Offset += Layout.getFieldOffset(idx);
+      Offset += Layout.getFieldOffset(MaybeFieldIdx.value());
       break;
     }
     }
diff --git a/clang/test/Analysis/modules/explicit-templ-inst-crash-in-modules.cppm b/clang/test/Analysis/modules/explicit-templ-inst-crash-in-modules.cppm
new file mode 100644
index 0000000000000..6eec29c7187ba
--- /dev/null
+++ b/clang/test/Analysis/modules/explicit-templ-inst-crash-in-modules.cppm
@@ -0,0 +1,35 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// DEFINE: %{common-flags}= -std=c++20 -I %t -fprebuilt-module-path=%t
+//
+// RUN: %clang_cc1 %{common-flags} %t/other.cppm -emit-module-interface -o %t/other.pcm
+// RUN: %clang_analyze_cc1 -analyzer-checker=core %{common-flags} %t/entry.cppm -verify
+
+
+//--- MyStruct.h
+template <typename T> struct MyStruct {
+  T data = 0;
+};
+template struct MyStruct<int>; // Explicit template instantiation.
+
+//--- other.cppm
+module;
+#include "MyStruct.h"
+export module other;
+static void implicit_instantiate_MyStruct() {
+  MyStruct<int> var;
+  (void)var;
+}
+
+//--- entry.cppm
+// expected-no-diagnostics
+module;
+#include "MyStruct.h"
+module other;
+
+void entry_point() {
+  MyStruct<int> var; // no-crash
+  (void)var;
+}