diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -250,6 +250,8 @@
 * A type-bound procedure binding can be passed as an actual
   argument corresponding to a dummy procedure and can be used as
   the target of a procedure pointer assignment statement.
+* An explicit `INTERFACE` can declare the interface of a
+  procedure pointer even if it is not a dummy argument.
 
 ### Extensions supported when enabled by options
 
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
@@ -3856,7 +3856,7 @@
   if (auto *prev{FindSymbol(name)}) {
     if (IsDummy(*prev)) {
     } else if (auto *entity{prev->detailsIf<EntityDetails>()};
-               IsPointer(*prev) && !entity->type()) {
+               IsPointer(*prev) && entity && !entity->type()) {
       // POINTER attribute set before interface
     } else if (inInterfaceBlock() && currScope() != prev->owner()) {
       // Procedures in an INTERFACE block do not resolve to symbols
@@ -4071,6 +4071,17 @@
     symbol.ReplaceName(name.source);
     EndArraySpec();
   } else {
+    if (const auto *symbol{FindInScope(name)}) {
+      const auto *subp{symbol->detailsIf<SubprogramDetails>()};
+      if (!symbol->has<UseDetails>() && // error caught elsewhere
+          !symbol->has<ObjectEntityDetails>() &&
+          !symbol->has<ProcEntityDetails>() &&
+          !symbol->CanReplaceDetails(ObjectEntityDetails{}) &&
+          !symbol->CanReplaceDetails(ProcEntityDetails{}) &&
+          !(subp && subp->isInterface())) {
+        Say(name, "'%s' cannot have the POINTER attribute"_err_en_US);
+      }
+    }
     HandleAttributeStmt(Attr::POINTER, std::get<parser::Name>(x.t));
   }
 }
diff --git a/flang/test/Semantics/pointer01.f90 b/flang/test/Semantics/pointer01.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Semantics/pointer01.f90
@@ -0,0 +1,37 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+module m
+  real mobj
+ contains
+  subroutine msubr
+  end subroutine
+end module
+program main
+  use m
+  !PORTABILITY: Name 'main' declared in a main program should not have the same name as the main program
+  pointer main
+  !ERROR: Cannot change POINTER attribute on use-associated 'mobj'
+  pointer mobj
+  !ERROR: Cannot change POINTER attribute on use-associated 'msubr'
+  pointer msubr
+  !ERROR: 'inner' cannot have the POINTER attribute
+  pointer inner
+  real obj
+  !ERROR: 'ip' may not have both the POINTER and PARAMETER attributes
+  integer, parameter :: ip = 123
+  pointer ip
+  type dt; end type
+  !ERROR: 'dt' cannot have the POINTER attribute
+  pointer dt
+  interface generic
+    subroutine extsub
+    end subroutine
+  end interface
+  !ERROR: 'generic' cannot have the POINTER attribute
+  pointer generic
+  namelist /nml/ obj
+  !ERROR: 'nml' cannot have the POINTER attribute
+  pointer nml
+ contains
+  subroutine inner
+  end subroutine
+end