diff --git a/pyciemss/mira_integration/compiled_dynamics.py b/pyciemss/mira_integration/compiled_dynamics.py
index 2cb668df6..27b24b1a3 100644
--- a/pyciemss/mira_integration/compiled_dynamics.py
+++ b/pyciemss/mira_integration/compiled_dynamics.py
@@ -159,7 +159,22 @@ def _eval_observables_mira(
     if len(src.observables) == 0:
         return dict()
 
-    numeric_observables = param_module.numeric_observables_func(**X)
+    parameters = {
+        get_name(param_info): getattr(param_module, get_name(param_info))
+        for param_info in src.parameters.values()
+        if not param_info.placeholder
+    }
+
+    # TODO: support event_dim > 0 upstream in ChiRho
+    # Default to time being the rightmost dimension
+    parameters_expanded = {
+        k: torch.unsqueeze(v, -1) if len(v.size()) > 0 else v
+        for k, v in parameters.items()
+    }
+
+    numeric_observables = param_module.numeric_observables_func(
+        **X, **parameters_expanded
+    )
 
     observables: State[torch.Tensor] = dict()
     for i, obs in enumerate(src.observables.values()):
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 06a627228..9ea0cd875 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -67,6 +67,13 @@ def __init__(
         ),
         "u",
     ),
+    ModelFixture(
+        os.path.join(MODELS_PATH, "SIR_param_in_observables.json"),
+        "beta",
+        os.path.join(DATA_PATH, "SIR_data_case_hosp.csv"),
+        {"case": "incident_cases", "hosp": "I"},
+        True,
+    ),
 ]
 
 REGNET_MODELS = [