diff --git a/jsonpath-compliance-test-suite b/jsonpath-compliance-test-suite
index ca076c0..446336c 160000
--- a/jsonpath-compliance-test-suite
+++ b/jsonpath-compliance-test-suite
@@ -1 +1 @@
-Subproject commit ca076c0e55d378236e7b70fc8e6414234dcca294
+Subproject commit 446336cd6651586f416a3b546c70bdd0fa2022c0
diff --git a/serde_json_path/CHANGELOG.md b/serde_json_path/CHANGELOG.md
index 64831f0..05d8818 100644
--- a/serde_json_path/CHANGELOG.md
+++ b/serde_json_path/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # Unreleased
 
+- **fixed**: bug preventing registered functions from being used as arguments to other functions ([#84])
+
+[#84]: https://github.com/hiltontj/serde_json_path/pull/84
+
 # 0.6.6 (23 February 2024)
 
 - **docs**: update links to refer to RFC 9535 ([#81])
diff --git a/serde_json_path/src/parser/selector/function/registry.rs b/serde_json_path/src/parser/selector/function/registry.rs
index bc88636..e52a3fc 100644
--- a/serde_json_path/src/parser/selector/function/registry.rs
+++ b/serde_json_path/src/parser/selector/function/registry.rs
@@ -9,6 +9,13 @@ use serde_json_path_core::spec::functions::{Function, LogicalType, NodesType, Va
 ///
 /// These come directly from the JSONPath specification, which includes a registry of standardized
 /// functions.
+///
+/// # Note
+///
+/// There is a function in `serde_json_path_core/src/spec/functions.rs` that gives
+/// the return type for each function registered here. When adding new functions to
+/// the register, i.e., when new functions are standardized, the function there needs
+/// to be updated too.
 pub(crate) static REGISTRY: Lazy<HashMap<&'static str, &'static Function>> = Lazy::new(|| {
     let mut m = HashMap::new();
     m.insert("length", &LENGTH_FUNC);
diff --git a/serde_json_path_core/CHANGELOG.md b/serde_json_path_core/CHANGELOG.md
index 3914a52..59ce670 100644
--- a/serde_json_path_core/CHANGELOG.md
+++ b/serde_json_path_core/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # Unreleased
 
+- **fixed**: bug preventing registered functions from being used as arguments to other functions ([#84])
+
+[#84]: https://github.com/hiltontj/serde_json_path/pull/84
+
 # 0.1.5 (23 February 2024)
 
 - **docs**: update links to refer to RFC 9535 ([#81])
diff --git a/serde_json_path_core/src/spec/functions.rs b/serde_json_path_core/src/spec/functions.rs
index c6a4abc..3a8d00b 100644
--- a/serde_json_path_core/src/spec/functions.rs
+++ b/serde_json_path_core/src/spec/functions.rs
@@ -618,14 +618,36 @@ impl FunctionExprArg {
                         return Ok(f.result_type);
                     }
                 }
-                Err(FunctionValidationError::Undefined {
-                    name: func.name.to_owned(),
+                registered_function_result_type(&func.name).ok_or_else(|| {
+                    FunctionValidationError::Undefined {
+                        name: func.name.to_owned(),
+                    }
                 })
             }
         }
     }
 }
 
+/// Get the result type of a registered function
+///
+/// This is a hack, but must be done, because the REGISTRY defined in `serde_json_path`
+/// is not accessible here. Therefore, this must also be maintained when new functions
+/// are added to the registry in the standard.
+///
+/// An alternative would be to define the registry of functions in core, we would then
+/// just not have the convenience macro for defining them, along with their validators
+/// and evaluators.
+fn registered_function_result_type(name: &str) -> Option<FunctionArgType> {
+    match name {
+        "length" => Some(FunctionArgType::Value),
+        "count" => Some(FunctionArgType::Value),
+        "match" => Some(FunctionArgType::Logical),
+        "search" => Some(FunctionArgType::Logical),
+        "value" => Some(FunctionArgType::Value),
+        _ => None,
+    }
+}
+
 /// Function argument types
 ///
 /// This is used to describe the type of a function argument to determine if it will be valid as a
diff --git a/serde_json_path_macros/CHANGELOG.md b/serde_json_path_macros/CHANGELOG.md
index d4d06ac..27e8930 100644
--- a/serde_json_path_macros/CHANGELOG.md
+++ b/serde_json_path_macros/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # Unreleased
 
+- **fixed**: bug preventing registered functions from being used as arguments to other functions ([#84])
+
+[#84]: https://github.com/hiltontj/serde_json_path/pull/84
+
 # 0.1.3 (23 February 2024)
 
 - **internal**: update serde_json_path_core dependency