diff --git a/llvm/include/llvm/ProfileData/SampleProf.h b/llvm/include/llvm/ProfileData/SampleProf.h
--- a/llvm/include/llvm/ProfileData/SampleProf.h
+++ b/llvm/include/llvm/ProfileData/SampleProf.h
@@ -515,6 +515,8 @@
   sampleprof_error merge(const FunctionSamples &Other, uint64_t Weight = 1) {
     sampleprof_error Result = sampleprof_error::success;
     Name = Other.getName();
+    if (!GUIDToFuncNameMap)
+      GUIDToFuncNameMap = Other.GUIDToFuncNameMap;
     MergeResult(Result, addTotalSamples(Other.getTotalSamples(), Weight));
     MergeResult(Result, addHeadSamples(Other.getHeadSamples(), Weight));
     for (const auto &I : Other.getBodySamples()) {
diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp
--- a/llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -995,6 +995,8 @@
         const FunctionSamples *FS = nullptr;
         if (auto *CB = dyn_cast<CallBase>(&I)) {
           if (!isa<IntrinsicInst>(I) && (FS = findCalleeFunctionSamples(*CB))) {
+            assert((!FunctionSamples::UseMD5 || FS->GUIDToFuncNameMap) &&
+                   "GUIDToFuncNameMap has to be populated");
             AllCandidates.push_back(CB);
             if (FS->getEntrySamples() > 0)
               localNotInlinedCallSites.try_emplace(CB, FS);
diff --git a/llvm/test/Transforms/SampleProfile/Inputs/inline-mergeprof.md5.prof b/llvm/test/Transforms/SampleProfile/Inputs/inline-mergeprof.md5.prof
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
GIT binary patch
literal 0
Hc$@<O00001

literal 0
Hc$@<O00001

diff --git a/llvm/test/Transforms/SampleProfile/inline-mergeprof.ll b/llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
--- a/llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
+++ b/llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
@@ -3,9 +3,13 @@
 ; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=true -S | FileCheck -check-prefix=SCALE %s
 ; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=false -S | FileCheck -check-prefix=SCALE %s
 
-; Test we properly merge not inlined profile properly with '-sample-profile-merge-inlinee'
+; Test we properly merge not inlined profile with '-sample-profile-merge-inlinee'
 ; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=true -S | FileCheck -check-prefix=MERGE  %s
 
+; Test we properly merge not inlined profile with '-sample-profile-merge-inlinee'
+; when the profile uses md5.
+; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.md5.prof -sample-profile-merge-inlinee=true -S | FileCheck -check-prefix=MERGE  %s
+
 @.str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align 1
 
 define i32 @main() #0 !dbg !6 {