diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h
index 5e9c07545ae1f..23a2756a18f69 100644
--- a/clang/lib/AST/Interp/Interp.h
+++ b/clang/lib/AST/Interp/Interp.h
@@ -135,7 +135,7 @@ bool CheckShift(InterpState &S, CodePtr OpPC, const LT &LHS, const RT &RHS,
     const APSInt Val = RHS.toAPSInt();
     QualType Ty = E->getType();
     S.CCEDiag(E, diag::note_constexpr_large_shift) << Val << Ty << Bits;
-    return false;
+    return true; // We will do the shift anyway but fix up the shift amount.
   }
 
   if (LHS.isSigned() && !S.getLangOpts().CPlusPlus20) {
@@ -1798,11 +1798,17 @@ inline bool Shr(InterpState &S, CodePtr OpPC) {
   if (!CheckShift(S, OpPC, LHS, RHS, Bits))
     return false;
 
+  // Limit the shift amount to Bits - 1. If this happened,
+  // it has already been diagnosed by CheckShift() above,
+  // but we still need to handle it.
   typename LT::AsUnsigned R;
-  LT::AsUnsigned::shiftRight(LT::AsUnsigned::from(LHS),
-                             LT::AsUnsigned::from(RHS), Bits, &R);
+  if (RHS > RT::from(Bits - 1, RHS.bitWidth()))
+    LT::AsUnsigned::shiftRight(LT::AsUnsigned::from(LHS),
+                               LT::AsUnsigned::from(Bits - 1), Bits, &R);
+  else
+    LT::AsUnsigned::shiftRight(LT::AsUnsigned::from(LHS),
+                               LT::AsUnsigned::from(RHS, Bits), Bits, &R);
   S.Stk.push<LT>(LT::from(R));
-
   return true;
 }
 
@@ -1817,9 +1823,17 @@ inline bool Shl(InterpState &S, CodePtr OpPC) {
   if (!CheckShift(S, OpPC, LHS, RHS, Bits))
     return false;
 
+  // Limit the shift amount to Bits - 1. If this happened,
+  // it has already been diagnosed by CheckShift() above,
+  // but we still need to handle it.
   typename LT::AsUnsigned R;
-  LT::AsUnsigned::shiftLeft(LT::AsUnsigned::from(LHS),
-                            LT::AsUnsigned::from(RHS, Bits), Bits, &R);
+  if (RHS > RT::from(Bits - 1, RHS.bitWidth()))
+    LT::AsUnsigned::shiftLeft(LT::AsUnsigned::from(LHS),
+                              LT::AsUnsigned::from(Bits - 1), Bits, &R);
+  else
+    LT::AsUnsigned::shiftLeft(LT::AsUnsigned::from(LHS),
+                              LT::AsUnsigned::from(RHS, Bits), Bits, &R);
+
   S.Stk.push<LT>(LT::from(R));
   return true;
 }
diff --git a/clang/test/AST/Interp/shifts.cpp b/clang/test/AST/Interp/shifts.cpp
index e5201b3f8bbef..76047d0f752d5 100644
--- a/clang/test/AST/Interp/shifts.cpp
+++ b/clang/test/AST/Interp/shifts.cpp
@@ -34,12 +34,13 @@ namespace shifts {
                  // ref-warning {{shift count is negative}} \
                  // ref-cxx17-warning {{shift count is negative}}
     c = 1 << (unsigned)-1; // expected-warning {{shift count >= width of type}} \
-                           // FIXME: 'implicit conversion' warning missing in the new interpreter. \
+                           // expected-warning {{implicit conversion from 'int' to 'char' changes value from -2147483648 to 0}} \
                            // cxx17-warning {{shift count >= width of type}} \
+                           // cxx17-warning {{implicit conversion from 'int' to 'char' changes value from -2147483648 to 0}} \
                            // ref-warning {{shift count >= width of type}} \
-                           // ref-warning {{implicit conversion}} \
+                           // ref-warning {{implicit conversion from 'int' to 'char' changes value from -2147483648 to 0}} \
                            // ref-cxx17-warning {{shift count >= width of type}} \
-                           // ref-cxx17-warning {{implicit conversion}}
+                           // ref-cxx17-warning {{implicit conversion from 'int' to 'char' changes value from -2147483648 to 0}}
     c = 1 >> (unsigned)-1; // expected-warning {{shift count >= width of type}} \
                            // cxx17-warning {{shift count >= width of type}} \
                            // ref-warning {{shift count >= width of type}} \