diff --git a/include/cantera/base/AnyMap.inl.h b/include/cantera/base/AnyMap.inl.h
index b87ff3c55..907133483 100644
--- a/include/cantera/base/AnyMap.inl.h
+++ b/include/cantera/base/AnyMap.inl.h
@@ -16,6 +16,10 @@ namespace Cantera
 template<class T>
 const T &AnyValue::as() const {
     try {
+        if (typeid(T) == typeid(double) && m_value->type() == typeid(long int)) {
+            // Implicit conversion of long int to double
+            *m_value = static_cast<double>(as<long int>());
+        }
         return boost::any_cast<const T&>(*m_value);
     } catch (boost::bad_any_cast&) {
         if (m_value->type() == typeid(void)) {
@@ -32,6 +36,10 @@ const T &AnyValue::as() const {
 template<class T>
 T &AnyValue::as() {
     try {
+        if (typeid(T) == typeid(double) && m_value->type() == typeid(long int)) {
+            // Implicit conversion of long int to double
+            *m_value = static_cast<double>(as<long int>());
+        }
         return boost::any_cast<T&>(*m_value);
     } catch (boost::bad_any_cast&) {
         if (m_value->type() == typeid(void)) {
@@ -107,13 +115,7 @@ std::map<std::string, T> AnyValue::asMap() const
 {
     std::map<std::string, T> dest;
     for (const auto& item : as<AnyMap>().m_data) {
-        try {
-            dest[item.first] = boost::any_cast<T>(*item.second.m_value);
-        } catch (boost::bad_any_cast&) {
-            throw CanteraError("AnyValue::asMap",
-                "Value of key '{}' is not a '{}'",
-                item.first, demangle(typeid(T)));
-        }
+        dest[item.first] = item.second.as<T>();
     }
     return dest;
 }
diff --git a/src/base/AnyMap.cpp b/src/base/AnyMap.cpp
index 1037d1c82..0c1325979 100644
--- a/src/base/AnyMap.cpp
+++ b/src/base/AnyMap.cpp
@@ -228,6 +228,7 @@ namespace Cantera
 
 std::map<std::string, std::string> AnyValue::s_typenames = {
     {typeid(double).name(), "double"},
+    {typeid(long int).name(), "long int"},
     {typeid(std::string).name(), "string"},
     {typeid(std::vector<double>).name(), "vector<double>"},
     {typeid(AnyMap).name(), "AnyMap"},
@@ -305,16 +306,10 @@ AnyValue &AnyValue::operator=(double value) {
 }
 
 double& AnyValue::asDouble() {
-    if (m_value->type() == typeid(long int)) {
-        *m_value = static_cast<double>(as<long int>());
-    }
     return as<double>();
 }
 
 const double& AnyValue::asDouble() const {
-    if (m_value->type() == typeid(long int)) {
-        *m_value = static_cast<double>(as<long int>());
-    }
     return as<double>();
 }
 
diff --git a/test/general/test_containers.cpp b/test/general/test_containers.cpp
index 23248ea13..9b25fc8b9 100644
--- a/test/general/test_containers.cpp
+++ b/test/general/test_containers.cpp
@@ -62,6 +62,13 @@ TEST(AnyMap, map_conversion) {
 
     EXPECT_THROW(m["foo"]["a"].asString(), CanteraError);
     EXPECT_THROW(m["foo"]["b"].asVector<double>(), CanteraError);
+
+    m["qux"]["c"] = 3;
+    m["qux"]["d"] = 3.14;
+    auto y = m["qux"].asMap<double>();
+    EXPECT_DOUBLE_EQ(y["c"], 3.0);
+    EXPECT_DOUBLE_EQ(y["d"], 3.14);
+    EXPECT_THROW(m["qux"].asMap<long int>(), CanteraError);
 }
 
 TEST(AnyMap, nested)