diff --git a/packages/seacas/libraries/aprepro_lib/apr_aprepro.cc b/packages/seacas/libraries/aprepro_lib/apr_aprepro.cc
index 48e2bd3a47..a20117a8e5 100644
--- a/packages/seacas/libraries/aprepro_lib/apr_aprepro.cc
+++ b/packages/seacas/libraries/aprepro_lib/apr_aprepro.cc
@@ -34,7 +34,7 @@
 #endif
 
 namespace {
-  const std::string version_short{"6.24"};
+  const std::string version_short{"6.25"};
   const std::string version_date{"(2023/10/12)"};
   const std::string version_string = version_short + " " + version_date;
 
diff --git a/packages/seacas/libraries/aprepro_lib/apr_scanner.cc b/packages/seacas/libraries/aprepro_lib/apr_scanner.cc
index bbda06b9e1..b8f74e9781 100644
--- a/packages/seacas/libraries/aprepro_lib/apr_scanner.cc
+++ b/packages/seacas/libraries/aprepro_lib/apr_scanner.cc
@@ -1396,51 +1396,60 @@ YY_DECL
             }
           }
 
-          temp_f = get_temp_filename();
-          SEAMS::file_rec new_file(temp_f, 0, true, loop_iterations);
-          outer_file          = &aprepro.ap_file_list.top();
-          new_file.loop_level = outer_file->loop_level + 1;
-
-          // Get optional loop index...
-          std::string sym_name;
-          if (tokens.size() == 1) {
-            // Default loop index variable name if not specified in loop command.
-            sym_name = fmt::format("__loop_{}", new_file.loop_level);
+          if (loop_iterations <= 0) {
+            BEGIN(LOOP_SKIP);
+            if (aprepro.ap_options.debugging) {
+              fmt::print(stderr, "DEBUG LOOP: iteration count = {}, Skipping loop...\n",
+                         loop_iterations);
+            }
           }
           else {
-            sym_name = tokens[1];
-          }
-          SEAMS::symrec *li = aprepro.getsym(sym_name);
-          if (li == nullptr) {
-            li = aprepro.putsym(sym_name, SEAMS::Aprepro::SYMBOL_TYPE::VARIABLE, true);
-          }
-
-          // Get optional loop index initial value.  Default to 0 if not specified.
-          double init = 0.0;
-          if (tokens.size() >= 3) {
-            init = std::stod(tokens[2]);
-          }
-          li->value.var = init;
+            temp_f = get_temp_filename();
+            SEAMS::file_rec new_file(temp_f, 0, true, loop_iterations);
+            outer_file          = &aprepro.ap_file_list.top();
+            new_file.loop_level = outer_file->loop_level + 1;
+
+            // Get optional loop index...
+            std::string sym_name;
+            if (tokens.size() == 1) {
+              // Default loop index variable name if not specified in loop command.
+              sym_name = fmt::format("__loop_{}", new_file.loop_level);
+            }
+            else {
+              sym_name = tokens[1];
+            }
+            SEAMS::symrec *li = aprepro.getsym(sym_name);
+            if (li == nullptr) {
+              li = aprepro.putsym(sym_name, SEAMS::Aprepro::SYMBOL_TYPE::VARIABLE, true);
+            }
 
-          // Get optional loop index increment value.  Default to 1 if not specified.
-          if (tokens.size() >= 4) {
-            double increment        = std::stod(tokens[3]);
-            new_file.loop_increment = increment;
-          }
+            // Get optional loop index initial value.  Default to 0 if not specified.
+            double init = 0.0;
+            if (tokens.size() >= 3) {
+              init = std::stod(tokens[2]);
+            }
+            li->value.var = init;
 
-          new_file.loop_index = li;
-          aprepro.ap_file_list.push(new_file);
+            // Get optional loop index increment value.  Default to 1 if not specified.
+            if (tokens.size() >= 4) {
+              double increment        = std::stod(tokens[3]);
+              new_file.loop_increment = increment;
+            }
 
-          tmp_file = new std::fstream(temp_f, std::ios::out);
-          loop_lvl++;
-          BEGIN(LOOP);
-          aprepro.isCollectingLoop = true;
-          if (aprepro.ap_options.debugging) {
-            fmt::print(
-                stderr,
-                "DEBUG LOOP: iteration count = {}, loop_index variable = {}, initial value = "
-                "{}, increment = {}\n",
-                loop_iterations, sym_name, init, new_file.loop_increment);
+            new_file.loop_index = li;
+            aprepro.ap_file_list.push(new_file);
+
+            tmp_file = new std::fstream(temp_f, std::ios::out);
+            loop_lvl++;
+            BEGIN(LOOP);
+            aprepro.isCollectingLoop = true;
+            if (aprepro.ap_options.debugging) {
+              fmt::print(
+                  stderr,
+                  "DEBUG LOOP: iteration count = {}, loop_index variable = {}, initial value = "
+                  "{}, increment = {}\n",
+                  loop_iterations, sym_name, init, new_file.loop_increment);
+            }
           }
         }
         YY_BREAK
diff --git a/packages/seacas/libraries/aprepro_lib/aprepro.ll b/packages/seacas/libraries/aprepro_lib/aprepro.ll
index 258a8523f9..5735e8aabb 100644
--- a/packages/seacas/libraries/aprepro_lib/aprepro.ll
+++ b/packages/seacas/libraries/aprepro_lib/aprepro.ll
@@ -177,48 +177,58 @@ integer {D}+({E})?
       }
     }
 
-    temp_f = get_temp_filename();
-    SEAMS::file_rec new_file(temp_f, 0, true, loop_iterations);
-    outer_file = &aprepro.ap_file_list.top();
-    new_file.loop_level = outer_file->loop_level + 1;
-
-    // Get optional loop index...
-    std::string sym_name;
-    if (tokens.size() == 1) {
-      // Default loop index variable name if not specified in loop command.
-      sym_name = fmt::format("__loop_{}", new_file.loop_level);
+    if (loop_iterations <= 0) {
+      BEGIN(LOOP_SKIP);
+      if (aprepro.ap_options.debugging) {
+	fmt::print(
+		   stderr,
+		   "DEBUG LOOP: iteration count = {}, Skipping loop...\n", loop_iterations);
+      }
     }
     else {
-      sym_name = tokens[1];
-    }
-    SEAMS::symrec *li = aprepro.getsym(sym_name);
-    if (li == nullptr) {
-      li = aprepro.putsym(sym_name, SEAMS::Aprepro::SYMBOL_TYPE::VARIABLE, true);
-    }
+      temp_f = get_temp_filename();
+      SEAMS::file_rec new_file(temp_f, 0, true, loop_iterations);
+      outer_file = &aprepro.ap_file_list.top();
+      new_file.loop_level = outer_file->loop_level + 1;
+
+      // Get optional loop index...
+      std::string sym_name;
+      if (tokens.size() == 1) {
+	// Default loop index variable name if not specified in loop command.
+	sym_name = fmt::format("__loop_{}", new_file.loop_level);
+      }
+      else {
+	sym_name = tokens[1];
+      }
+      SEAMS::symrec *li = aprepro.getsym(sym_name);
+      if (li == nullptr) {
+	li = aprepro.putsym(sym_name, SEAMS::Aprepro::SYMBOL_TYPE::VARIABLE, true);
+      }
 
-    // Get optional loop index initial value.  Default to 0 if not specified.
-    double init = 0.0;
-    if (tokens.size() >= 3) {
-      init = std::stod(tokens[2]);
-    }
-    li->value.var       = init;
+      // Get optional loop index initial value.  Default to 0 if not specified.
+      double init = 0.0;
+      if (tokens.size() >= 3) {
+	init = std::stod(tokens[2]);
+      }
+      li->value.var       = init;
 
-    // Get optional loop index increment value.  Default to 1 if not specified.
-    if (tokens.size() >= 4) {
-      double increment = std::stod(tokens[3]);
-      new_file.loop_increment = increment;
-    }
+      // Get optional loop index increment value.  Default to 1 if not specified.
+      if (tokens.size() >= 4) {
+	double increment = std::stod(tokens[3]);
+	new_file.loop_increment = increment;
+      }
 
-    new_file.loop_index = li;
-    aprepro.ap_file_list.push(new_file);
+      new_file.loop_index = li;
+      aprepro.ap_file_list.push(new_file);
 
-    tmp_file = new std::fstream(temp_f, std::ios::out);
-    loop_lvl++;
-    BEGIN(LOOP);
-    aprepro.isCollectingLoop = true;
-    if (aprepro.ap_options.debugging) {
-      fmt::print(stderr, "DEBUG LOOP: iteration count = {}, loop_index variable = {}, initial value = {}, increment = {}\n",
-		 loop_iterations, sym_name, init, new_file.loop_increment);
+      tmp_file = new std::fstream(temp_f, std::ios::out);
+      loop_lvl++;
+      BEGIN(LOOP);
+      aprepro.isCollectingLoop = true;
+      if (aprepro.ap_options.debugging) {
+	fmt::print(stderr, "DEBUG LOOP: iteration count = {}, loop_index variable = {}, initial value = {}, increment = {}\n",
+		   loop_iterations, sym_name, init, new_file.loop_increment);
+      }
     }
   }
 }
diff --git a/packages/seacas/libraries/aprepro_lib/test.inp_app b/packages/seacas/libraries/aprepro_lib/test.inp_app
index e89ca173fb..ec54c83b1f 100644
--- a/packages/seacas/libraries/aprepro_lib/test.inp_app
+++ b/packages/seacas/libraries/aprepro_lib/test.inp_app
@@ -251,4 +251,10 @@ $ Test string tokenization optimization
 Word {_i} of list1 and list2 are {get_word(_i,list1,',')} and {get_word(_i,list2,',')}
 {endloop}
 
+{loop(0)}
+This should not be echoed
+{endloop}
+{loop(undefined)}
+This should not be echoed
+{endloop}
 $End of test file