diff --git a/src/dmd/dsymbol.d b/src/dmd/dsymbol.d
index afc5cf3d9ab6..5685a869c517 100644
--- a/src/dmd/dsymbol.d
+++ b/src/dmd/dsymbol.d
@@ -349,7 +349,7 @@ extern (C++) class Dsymbol : ASTNode
 
     final bool checkDeprecated(const ref Loc loc, Scope* sc)
     {
-        if (global.params.useDeprecated != Diagnostic.off && isDeprecated())
+        if (global.params.useDeprecated != DiagnosticReporting.off && isDeprecated())
         {
             // Don't complain if we're inside a deprecated symbol's scope
             if (sc.isDeprecated())
diff --git a/src/dmd/errors.d b/src/dmd/errors.d
index 064115e64d3f..0bce5111346b 100644
--- a/src/dmd/errors.d
+++ b/src/dmd/errors.d
@@ -322,12 +322,12 @@ extern (C++) void verrorSupplemental(const ref Loc loc, const(char)* format, va_
  */
 extern (C++) void vwarning(const ref Loc loc, const(char)* format, va_list ap)
 {
-    if (global.params.warnings != Diagnostic.off)
+    if (global.params.warnings != DiagnosticReporting.off)
     {
         if (!global.gag)
         {
             verrorPrint(loc, Classification.warning, "Warning: ", format, ap);
-            if (global.params.warnings == Diagnostic.error)
+            if (global.params.warnings == DiagnosticReporting.error)
                 global.warnings++;
         }
         else
@@ -346,7 +346,7 @@ extern (C++) void vwarning(const ref Loc loc, const(char)* format, va_list ap)
  */
 extern (C++) void vwarningSupplemental(const ref Loc loc, const(char)* format, va_list ap)
 {
-    if (global.params.warnings != Diagnostic.off && !global.gag)
+    if (global.params.warnings != DiagnosticReporting.off && !global.gag)
         verrorPrint(loc, Classification.warning, "       ", format, ap);
 }
 
@@ -362,9 +362,9 @@ extern (C++) void vwarningSupplemental(const ref Loc loc, const(char)* format, v
 extern (C++) void vdeprecation(const ref Loc loc, const(char)* format, va_list ap, const(char)* p1 = null, const(char)* p2 = null)
 {
     __gshared const(char)* header = "Deprecation: ";
-    if (global.params.useDeprecated == Diagnostic.error)
+    if (global.params.useDeprecated == DiagnosticReporting.error)
         verror(loc, format, ap, p1, p2, header);
-    else if (global.params.useDeprecated == Diagnostic.inform)
+    else if (global.params.useDeprecated == DiagnosticReporting.inform)
     {
         if (!global.gag)
         {
@@ -408,9 +408,9 @@ extern (C++) void vmessage(const ref Loc loc, const(char)* format, va_list ap)
  */
 extern (C++) void vdeprecationSupplemental(const ref Loc loc, const(char)* format, va_list ap)
 {
-    if (global.params.useDeprecated == Diagnostic.error)
+    if (global.params.useDeprecated == DiagnosticReporting.error)
         verrorSupplemental(loc, format, ap);
-    else if (global.params.useDeprecated == Diagnostic.inform && !global.gag)
+    else if (global.params.useDeprecated == DiagnosticReporting.inform && !global.gag)
         verrorPrint(loc, Classification.deprecation, "       ", format, ap);
 }
 
diff --git a/src/dmd/expressionsem.d b/src/dmd/expressionsem.d
index dc5adf2ceb55..c63175596341 100644
--- a/src/dmd/expressionsem.d
+++ b/src/dmd/expressionsem.d
@@ -8530,7 +8530,7 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
                     return setError();
             }
 
-            if (0 && global.params.warnings != Diagnostic.off && !global.gag && exp.op == TOK.assign &&
+            if (0 && global.params.warnings != DiagnosticReporting.off && !global.gag && exp.op == TOK.assign &&
                 e2x.op != TOK.slice && e2x.op != TOK.assign &&
                 e2x.op != TOK.arrayLiteral && e2x.op != TOK.string_ &&
                 !(e2x.op == TOK.add || e2x.op == TOK.min ||
@@ -8594,7 +8594,7 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
         }
         else
         {
-            if (0 && global.params.warnings != Diagnostic.off && !global.gag && exp.op == TOK.assign &&
+            if (0 && global.params.warnings != DiagnosticReporting.off && !global.gag && exp.op == TOK.assign &&
                 t1.ty == Tarray && t2.ty == Tsarray &&
                 e2x.op != TOK.slice &&
                 t2.implicitConvTo(t1))
diff --git a/src/dmd/globals.d b/src/dmd/globals.d
index f2853bbd5756..0ea8a23a91f2 100644
--- a/src/dmd/globals.d
+++ b/src/dmd/globals.d
@@ -34,7 +34,7 @@ enum TARGET : bool
     DragonFlyBSD = xversion!`DragonFlyBSD`,
 }
 
-enum Diagnostic : ubyte
+enum DiagnosticReporting : ubyte
 {
     error,        // generate an error
     inform,       // generate a warning
@@ -132,7 +132,7 @@ struct Param
     bool isSolaris;         // generate code for Solaris
     bool hasObjectiveC;     // target supports Objective-C
     bool mscoff = false;    // for Win32: write MsCoff object files instead of OMF
-    Diagnostic useDeprecated = Diagnostic.inform;  // how use of deprecated features are handled
+    DiagnosticReporting useDeprecated = DiagnosticReporting.inform;  // how use of deprecated features are handled
     bool stackstomp;            // add stack stomping code
     bool useUnitTests;          // generate unittest code
     bool useInline = false;     // inline expand functions
@@ -140,7 +140,7 @@ struct Param
     bool noDIP25;           // revert to pre-DIP25 behavior
     bool release;           // build release version
     bool preservePaths;     // true means don't strip path from source file
-    Diagnostic warnings = Diagnostic.off;  // how compiler warnings are handled
+    DiagnosticReporting warnings = DiagnosticReporting.off;  // how compiler warnings are handled
     bool pic;               // generate position-independent-code for shared libs
     bool color;             // use ANSI colors in console output
     bool cov;               // generate code coverage data
diff --git a/src/dmd/lexer.d b/src/dmd/lexer.d
index 2ad44e72223c..97a7ae03fe3a 100644
--- a/src/dmd/lexer.d
+++ b/src/dmd/lexer.d
@@ -333,7 +333,7 @@ This is usually the default diagnostic reporter.
 */
 final class StderrDiagnosticReporter : DiagnosticReporter
 {
-    private const Diagnostic useDeprecated;
+    private const DiagnosticReporting useDeprecated;
 
     private int errorCount_;
     private int warningCount_;
@@ -346,7 +346,7 @@ final class StderrDiagnosticReporter : DiagnosticReporter
         useDeprecated = indicates how deprecation diagnostics should be
             handled
     */
-    this(Diagnostic useDeprecated)
+    this(DiagnosticReporting useDeprecated)
     {
         this.useDeprecated = useDeprecated;
     }
@@ -392,7 +392,7 @@ final class StderrDiagnosticReporter : DiagnosticReporter
     {
         vdeprecation(loc, format, args);
 
-        if (useDeprecated == Diagnostic.error)
+        if (useDeprecated == DiagnosticReporting.error)
             errorCount_++;
         else
             deprecationCount_++;
diff --git a/src/dmd/mars.d b/src/dmd/mars.d
index 3de3ba1f478c..3fa37daeb9ea 100644
--- a/src/dmd/mars.d
+++ b/src/dmd/mars.d
@@ -1573,11 +1573,11 @@ bool parseCommandLine(const ref Strings arguments, const size_t argc, ref Param
         if (arg == "-allinst")               // https://dlang.org/dmd.html#switch-allinst
             params.allInst = true;
         else if (arg == "-de")               // https://dlang.org/dmd.html#switch-de
-            params.useDeprecated = Diagnostic.error;
+            params.useDeprecated = DiagnosticReporting.error;
         else if (arg == "-d")                // https://dlang.org/dmd.html#switch-d
-            params.useDeprecated = Diagnostic.off;
+            params.useDeprecated = DiagnosticReporting.off;
         else if (arg == "-dw")               // https://dlang.org/dmd.html#switch-dw
-            params.useDeprecated = Diagnostic.inform;
+            params.useDeprecated = DiagnosticReporting.inform;
         else if (arg == "-c")                // https://dlang.org/dmd.html#switch-c
             params.link = false;
         else if (startsWith(p + 1, "checkaction")) // https://dlang.org/dmd.html#switch-checkaction
@@ -2009,9 +2009,9 @@ bool parseCommandLine(const ref Strings arguments, const size_t argc, ref Param
                 params.useDIP25 = false;
         }
         else if (arg == "-w")   // https://dlang.org/dmd.html#switch-w
-            params.warnings = Diagnostic.error;
+            params.warnings = DiagnosticReporting.error;
         else if (arg == "-wi")  // https://dlang.org/dmd.html#switch-wi
-            params.warnings = Diagnostic.inform;
+            params.warnings = DiagnosticReporting.inform;
         else if (arg == "-O")   // https://dlang.org/dmd.html#switch-O
             params.optimize = true;
         else if (p[1] == 'o')
diff --git a/src/dmd/semantic3.d b/src/dmd/semantic3.d
index dedfd6c858a2..0bc6b1870d5e 100644
--- a/src/dmd/semantic3.d
+++ b/src/dmd/semantic3.d
@@ -1384,7 +1384,7 @@ private extern(C++) final class Semantic3Visitor : Visitor
 
         // don't do it for unused deprecated types
         // or error ypes
-        if (!ad.getRTInfo && Type.rtinfo && (!ad.isDeprecated() || global.params.useDeprecated != Diagnostic.error) && (ad.type && ad.type.ty != Terror))
+        if (!ad.getRTInfo && Type.rtinfo && (!ad.isDeprecated() || global.params.useDeprecated != DiagnosticReporting.error) && (ad.type && ad.type.ty != Terror))
         {
             // Evaluate: RTinfo!type
             auto tiargs = new Objects();
diff --git a/src/dmd/sideeffect.d b/src/dmd/sideeffect.d
index 98108ca223c4..f9e321512e9b 100644
--- a/src/dmd/sideeffect.d
+++ b/src/dmd/sideeffect.d
@@ -251,7 +251,7 @@ bool discardValue(Expression e)
         }
     case TOK.call:
         /* Issue 3882: */
-        if (global.params.warnings != Diagnostic.off && !global.gag)
+        if (global.params.warnings != DiagnosticReporting.off && !global.gag)
         {
             CallExp ce = cast(CallExp)e;
             if (e.type.ty == Tvoid)