diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -301,6 +301,8 @@
   expressions/statements with invalid source locations in non-assert builds. 
   Assert builds may still see assertions triggered from this.
   (`#62105 <https://github.com/llvm/llvm-project/issues/62105>`_)
+- Fix crash after suggesting typo correction to constexpr if condition.
+  (`#61885 <https://github.com/llvm/llvm-project/issues/61885>`_)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -12849,11 +12849,17 @@
     friend class Sema;
     ConditionResult(Sema &S, Decl *ConditionVar, FullExprArg Condition,
                     bool IsConstexpr)
-        : ConditionVar(ConditionVar), Condition(Condition), Invalid(false),
-          HasKnownValue(IsConstexpr && Condition.get() &&
-                        !Condition.get()->isValueDependent()),
-          KnownValue(HasKnownValue &&
-                     !!Condition.get()->EvaluateKnownConstInt(S.Context)) {}
+        : ConditionVar(ConditionVar), Condition(Condition), Invalid(false) {
+      if (IsConstexpr && Condition.get()) {
+        if (std::optional<llvm::APSInt> Val =
+                Condition.get()->getIntegerConstantExpr(S.Context)) {
+          KnownValue = !!(*Val);
+          HasKnownValue = true;
+        }
+      } else {
+        HasKnownValue = false;
+      }
+    }
     explicit ConditionResult(bool Invalid)
         : ConditionVar(nullptr), Condition(nullptr), Invalid(Invalid),
           HasKnownValue(false), KnownValue(false) {}
diff --git a/clang/test/SemaCXX/invalid-if-constexpr.cpp b/clang/test/SemaCXX/invalid-if-constexpr.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/SemaCXX/invalid-if-constexpr.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -verify -std=c++20 %s
+
+namespace GH61885 {
+void similar() { // expected-note {{'similar' declared here}}
+  if constexpr (similer<>) {} // expected-error {{use of undeclared identifier 'similer'; did you mean 'similar'?}}
+}
+void a() { if constexpr (__adl_swap<>) {}} // expected-error{{use of undeclared identifier '__adl_swap'; did you mean '__sync_swap'?}} \
+                                           // expected-note {{'__sync_swap' declared here}}
+
+int AA() { return true;} // expected-note {{'AA' declared here}}
+
+void b() { if constexpr (AAA<>) {}} // expected-error {{use of undeclared identifier 'AAA'; did you mean 'AA'?}}
+}
+