diff --git a/flang/include/flang/Semantics/symbol.h b/flang/include/flang/Semantics/symbol.h
--- a/flang/include/flang/Semantics/symbol.h
+++ b/flang/include/flang/Semantics/symbol.h
@@ -219,10 +219,7 @@
 
   const ProcInterface &interface() const { return interface_; }
   ProcInterface &interface() { return interface_; }
-  void set_interface(const ProcInterface &interface) {
-    CHECK(!IsInterfaceSet());
-    interface_ = interface;
-  }
+  void set_interface(const ProcInterface &interface) { interface_ = interface; }
   bool IsInterfaceSet() {
     return interface_.symbol() != nullptr || interface_.type() != nullptr;
   }
diff --git a/flang/lib/Semantics/compute-offsets.cpp b/flang/lib/Semantics/compute-offsets.cpp
--- a/flang/lib/Semantics/compute-offsets.cpp
+++ b/flang/lib/Semantics/compute-offsets.cpp
@@ -257,7 +257,7 @@
   // TODO: The size of procedure pointers is not yet known
   // and is independent of rank (and probably also the number
   // of length type parameters).
-  if (IsDescriptor(symbol) || IsProcedure(symbol)) {
+  if (IsDescriptor(symbol) || IsProcedurePointer(symbol)) {
     int lenParams{0};
     if (const DerivedTypeSpec * derived{type->AsDerived()}) {
       lenParams = CountLenParameters(*derived);
@@ -266,6 +266,9 @@
         runtime::Descriptor::SizeInBytes(symbol.Rank(), false, lenParams)};
     return {size, maxAlignment};
   }
+  if (IsProcedure(symbol)) {
+    return {};
+  }
   SizeAndAlignment result;
   if (const IntrinsicTypeSpec * intrinsic{type->AsIntrinsic()}) {
     if (auto kind{ToInt64(intrinsic->kind())}) {
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -157,6 +157,9 @@
   evaluate::FoldingContext &GetFoldingContext() const {
     return context_->foldingContext();
   }
+  bool IsIntrinsic(const SourceName &name) const {
+    return context_->intrinsics().IsIntrinsic(name.ToString());
+  }
 
   // Make a placeholder symbol for a Name that otherwise wouldn't have one.
   // It is not in any scope and always has MiscDetails.
@@ -2377,14 +2380,14 @@
                  },
           symbol.details());
 }
+
 void ScopeHandler::ApplyImplicitRules(Symbol &symbol) {
   if (NeedsType(symbol)) {
     if (const DeclTypeSpec * type{GetImplicitType(symbol)}) {
       symbol.set(Symbol::Flag::Implicit);
       symbol.SetType(*type);
     } else if (symbol.has<ProcEntityDetails>() &&
-        !symbol.attrs().test(Attr::EXTERNAL) &&
-        context().intrinsics().IsIntrinsic(symbol.name().ToString())) {
+        !symbol.attrs().test(Attr::EXTERNAL) && IsIntrinsic(symbol.name())) {
       // type will be determined in expression semantics
       symbol.attrs().set(Attr::INTRINSIC);
     } else if (!context().HasError(symbol)) {
@@ -2393,6 +2396,7 @@
     }
   }
 }
+
 const DeclTypeSpec *ScopeHandler::GetImplicitType(Symbol &symbol) {
   const DeclTypeSpec *type{implicitRules().GetType(symbol.name().begin()[0])};
   if (type) {
@@ -3616,8 +3620,7 @@
 }
 Symbol &DeclarationVisitor::HandleAttributeStmt(
     Attr attr, const parser::Name &name) {
-  if (attr == Attr::INTRINSIC &&
-      !context().intrinsics().IsIntrinsic(name.source.ToString())) {
+  if (attr == Attr::INTRINSIC && !IsIntrinsic(name.source)) {
     Say(name.source, "'%s' is not a known intrinsic procedure"_err_en_US);
   }
   auto *symbol{FindInScope(currScope(), name)};
@@ -6055,7 +6058,7 @@
   CHECK(flag == Symbol::Flag::Function || flag == Symbol::Flag::Subroutine);
   auto *symbol{FindSymbol(NonDerivedTypeScope(), name)};
   if (!symbol) {
-    if (context().intrinsics().IsIntrinsic(name.source.ToString())) {
+    if (IsIntrinsic(name.source)) {
       symbol =
           &MakeSymbol(InclusiveScope(), name.source, Attrs{Attr::INTRINSIC});
     } else {
@@ -6084,7 +6087,11 @@
     // error was reported
   } else {
     symbol = &Resolve(name, symbol)->GetUltimate();
-    ConvertToProcEntity(*symbol);
+    if (ConvertToProcEntity(*symbol) && IsIntrinsic(symbol->name())) {
+      symbol->attrs().set(Attr::INTRINSIC);
+      // 8.2(3): ignore type from intrinsic in type-declaration-stmt
+      symbol->get<ProcEntityDetails>().set_interface(ProcInterface{});
+    }
     if (!SetProcFlag(name, *symbol, flag)) {
       return; // reported error
     }
diff --git a/flang/test/Semantics/symbol18.f90 b/flang/test/Semantics/symbol18.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Semantics/symbol18.f90
@@ -0,0 +1,21 @@
+! RUN: %S/test_symbols.sh %s %t %f18
+
+! Intrinsic function in type declaration statement: type is ignored
+
+!DEF: /p1 MainProgram
+program p1
+ !DEF: /p1/cos INTRINSIC (Function) ProcEntity
+ integer cos
+ !DEF: /p1/y (Implicit) ObjectEntity REAL(4)
+ !REF: /p1/cos
+ !DEF: /p1/x (Implicit) ObjectEntity REAL(4)
+ y = cos(x)
+ !REF: /p1/y
+ !DEF: /p1/sin INTRINSIC (Function) ProcEntity
+ !REF: /p1/x
+ y = sin(x)
+ !REF: /p1/y
+ !DEF: /f EXTERNAL (Function, Implicit) ProcEntity REAL(4)
+ !REF: /p1/x
+ y = f(x)
+end program