diff --git a/include/cantera/kinetics/Falloff.h b/include/cantera/kinetics/Falloff.h
index 4c282815ee..c982b4aba0 100644
--- a/include/cantera/kinetics/Falloff.h
+++ b/include/cantera/kinetics/Falloff.h
@@ -169,7 +169,7 @@ class FalloffRate : public ReactionRate
         return 0;
     }
 
-    virtual const std::string type() const {
+    virtual const std::string type() const override {
         if (m_chemicallyActivated) {
             return "chemically-activated";
         }
@@ -182,7 +182,8 @@ class FalloffRate : public ReactionRate
         return 0;
     }
 
-    virtual void setParameters(const AnyMap& node, const UnitStack& rate_units);
+    virtual void setParameters(
+        const AnyMap& node, const UnitStack& rate_units) override;
 
     //! Get the values of the parameters for this object. *params* must be an
     //! array of at least nParameters() elements.
@@ -223,7 +224,7 @@ class FalloffRate : public ReactionRate
     }
 
     virtual void check(const std::string& equation) override;
-    virtual void validate(const std::string& equation, const Kinetics& kin);
+    virtual void validate(const std::string& equation, const Kinetics& kin) override;
 
     //! Get flag indicating whether negative A values are permitted
     bool allowNegativePreExponentialFactor() const {
@@ -300,7 +301,7 @@ class LindemannRate final : public FalloffRate
         setFalloffCoeffs(c);
     }
 
-    unique_ptr<MultiRateBase> newMultiRate() const {
+    unique_ptr<MultiRateBase> newMultiRate() const override{
         return unique_ptr<MultiRateBase>(
             new MultiRate<LindemannRate, FalloffData>);
     }
@@ -361,7 +362,7 @@ class TroeRate final : public FalloffRate
         setFalloffCoeffs(c);
     }
 
-    unique_ptr<MultiRateBase> newMultiRate() const {
+    unique_ptr<MultiRateBase> newMultiRate() const override {
         return unique_ptr<MultiRateBase>(new MultiRate<TroeRate, FalloffData>);
     }
 
@@ -370,9 +371,9 @@ class TroeRate final : public FalloffRate
      * @param c Vector of three or four doubles: The doubles are the parameters,
      *          a, T_3, T_1, and (optionally) T_2 of the Troe parameterization
      */
-    virtual void setFalloffCoeffs(const vector_fp& c);
+    virtual void setFalloffCoeffs(const vector_fp& c) override;
 
-    virtual void getFalloffCoeffs(vector_fp& c) const;
+    virtual void getFalloffCoeffs(vector_fp& c) const override;
 
     //! Update the temperature parameters in the representation
     /*!
@@ -380,11 +381,11 @@ class TroeRate final : public FalloffRate
      *   @param work      Vector of working space, length 1, representing the
      *                    temperature-dependent part of the parameterization.
      */
-    virtual void updateTemp(double T, double* work) const;
+    virtual void updateTemp(double T, double* work) const override;
 
-    virtual double F(double pr, const double* work) const;
+    virtual double F(double pr, const double* work) const override;
 
-    virtual size_t workSize() const {
+    virtual size_t workSize() const override {
         return 1;
     }
 
@@ -392,19 +393,20 @@ class TroeRate final : public FalloffRate
         return "Troe";
     }
 
-    virtual size_t nParameters() const {
+    virtual size_t nParameters() const override {
         return 4;
     }
 
-    virtual void setParameters(const AnyMap& node, const UnitStack& rate_units);
+    virtual void setParameters(
+        const AnyMap& node, const UnitStack& rate_units) override;
 
     //! Sets params to contain, in order, \f[ (A, T_3, T_1, T_2) \f]
     /**
      * @deprecated  To be removed after Cantera 3.0; superseded by getFalloffCoeffs()
      */
-    virtual void getParameters(double* params) const;
+    virtual void getParameters(double* params) const override;
 
-    virtual void getParameters(AnyMap& node) const;
+    virtual void getParameters(AnyMap& node) const override;
 
 protected:
     //! parameter a in the 4-parameter Troe falloff function. Dimensionless
@@ -463,7 +465,7 @@ class SriRate final : public FalloffRate
         setFalloffCoeffs(c);
     }
 
-    unique_ptr<MultiRateBase> newMultiRate() const {
+    unique_ptr<MultiRateBase> newMultiRate() const override {
         return unique_ptr<MultiRateBase>(new MultiRate<SriRate, FalloffData>);
     }
 
@@ -473,9 +475,9 @@ class SriRate final : public FalloffRate
      *          a, b, c, d (optional; default 1.0), and e (optional; default
      *          0.0) of the SRI parameterization
      */
-    virtual void setFalloffCoeffs(const vector_fp& c);
+    virtual void setFalloffCoeffs(const vector_fp& c) override;
 
-    virtual void getFalloffCoeffs(vector_fp& c) const;
+    virtual void getFalloffCoeffs(vector_fp& c) const override;
 
     //! Update the temperature parameters in the representation
     /*!
@@ -483,11 +485,11 @@ class SriRate final : public FalloffRate
      *   @param work      Vector of working space, length 2, representing the
      *                    temperature-dependent part of the parameterization.
      */
-    virtual void updateTemp(double T, double* work) const;
+    virtual void updateTemp(double T, double* work) const override;
 
-    virtual double F(double pr, const double* work) const;
+    virtual double F(double pr, const double* work) const override;
 
-    virtual size_t workSize() const {
+    virtual size_t workSize() const override {
         return 2;
     }
 
@@ -495,19 +497,20 @@ class SriRate final : public FalloffRate
         return "SRI";
     }
 
-    virtual size_t nParameters() const {
+    virtual size_t nParameters() const override {
         return 5;
     }
 
-    virtual void setParameters(const AnyMap& node, const UnitStack& rate_units);
+    virtual void setParameters(
+        const AnyMap& node, const UnitStack& rate_units) override;
 
     //! Sets params to contain, in order, \f[ (a, b, c, d, e) \f]
     /**
      * @deprecated  To be removed after Cantera 3.0; superseded by getFalloffCoeffs()
      */
-    virtual void getParameters(double* params) const;
+    virtual void getParameters(double* params) const override;
 
-    virtual void getParameters(AnyMap& node) const;
+    virtual void getParameters(AnyMap& node) const override;
 
 protected:
     //! parameter a in the 5-parameter SRI falloff function. Dimensionless.
@@ -573,7 +576,7 @@ class TsangRate final : public FalloffRate
         setFalloffCoeffs(c);
     }
 
-    unique_ptr<MultiRateBase> newMultiRate() const {
+    unique_ptr<MultiRateBase> newMultiRate() const override {
         return unique_ptr<MultiRateBase>(new MultiRate<TsangRate, FalloffData>);
     }
 
@@ -582,9 +585,9 @@ class TsangRate final : public FalloffRate
      * @param c Vector of one or two doubles: The doubles are the parameters,
      *          a and (optionally) b of the Tsang F_cent parameterization
      */
-    virtual void setFalloffCoeffs(const vector_fp& c);
+    virtual void setFalloffCoeffs(const vector_fp& c) override;
 
-    virtual void getFalloffCoeffs(vector_fp& c) const;
+    virtual void getFalloffCoeffs(vector_fp& c) const override;
 
     //! Update the temperature parameters in the representation
     /*!
@@ -592,11 +595,11 @@ class TsangRate final : public FalloffRate
      *   @param work      Vector of working space, length 1, representing the
      *                    temperature-dependent part of the parameterization.
      */
-    virtual void updateTemp(double T, double* work) const;
+    virtual void updateTemp(double T, double* work) const override;
 
-    virtual double F(double pr, const double* work) const;
+    virtual double F(double pr, const double* work) const override;
 
-    virtual size_t workSize() const {
+    virtual size_t workSize() const override {
         return 1;
     }
 
@@ -604,19 +607,20 @@ class TsangRate final : public FalloffRate
         return "Tsang";
     }
 
-    virtual size_t nParameters() const {
+    virtual size_t nParameters() const override {
         return 2;
     }
 
-    virtual void setParameters(const AnyMap& node, const UnitStack& rate_units);
+    virtual void setParameters(
+        const AnyMap& node, const UnitStack& rate_units) override;
 
     //! Sets params to contain, in order, \f[ (A, B) \f]
     /**
      * @deprecated  To be removed after Cantera 3.0; superseded by getFalloffCoeffs()
      */
-    virtual void getParameters(double* params) const;
+    virtual void getParameters(double* params) const override;
 
-    virtual void getParameters(AnyMap& node) const;
+    virtual void getParameters(AnyMap& node) const override;
 
 protected:
     //! parameter a in the Tsang F_cent formulation. Dimensionless
diff --git a/interfaces/cython/cantera/reaction.pyx b/interfaces/cython/cantera/reaction.pyx
index b4536a6472..63344c7982 100644
--- a/interfaces/cython/cantera/reaction.pyx
+++ b/interfaces/cython/cantera/reaction.pyx
@@ -1488,7 +1488,7 @@ cdef class Reaction:
 
     property third_body:
         """
-        Returns an `ThirdBody` object if `Reaction` uses a third body collider, and
+        Returns a `ThirdBody` object if `Reaction` uses a third body collider, and
         ``None`` otherwise.
 
         .. versionadded:: 3.0
diff --git a/src/kinetics/Reaction.cpp b/src/kinetics/Reaction.cpp
index 0312a22c34..87d5252ca3 100644
--- a/src/kinetics/Reaction.cpp
+++ b/src/kinetics/Reaction.cpp
@@ -252,7 +252,7 @@ void Reaction::setRate(shared_ptr<ReactionRate> rate)
         if (rate_type == "falloff" || rate_type == "chemically-activated") {
             if (!m_from_composition) {
                 throw InputFileError("Reaction::setRate", input,
-                    "Reaction eqution for falloff reaction '{}'\n does not "
+                    "Reaction equation for falloff reaction '{}'\n does not "
                     "contain valid pressure-dependent third body", equation());
             }
             m_third_body.reset(new ThirdBody("(+M)"));
@@ -317,9 +317,6 @@ void Reaction::setEquation(const std::string& equation, const Kinetics* kin)
         // user override
         m_explicit_rate = true;
         return;
-    } else if (rate_type == "two-temperature-plasma") {
-        // two-temperature-plasma reactions do not use third bodies
-        return;
     } else if (kin && kin->thermo(kin->reactionPhaseIndex()).nDim() != 3) {
         // interface reactions
         return;
@@ -332,7 +329,8 @@ void Reaction::setEquation(const std::string& equation, const Kinetics* kin)
         // detect explicitly specified collision partner
         if (products.count(reac.first)) {
             third_body = reac.first;
-            size_t generic = third_body == "M" || ba::ends_with(third_body, "M)");
+            size_t generic = third_body == "M"
+                || third_body == "(+M)"  || third_body == "(+ M)";
             count++;
             countM += generic;
             if (reac.second > 1 && products[third_body] > 1) {
@@ -667,10 +665,6 @@ void ThirdBody::setName(const std::string& third_body)
             "Conflicting efficiency definition for explicit third body '{}'", name);
     }
     m_name = name;
-    if (name == "<multiple>") {
-        // sentinel value for multiple third body colliders
-        return;
-    }
     default_efficiency = 0.;
     efficiencies[m_name] = 1.;
 }
diff --git a/test/kinetics/kineticsFromYaml.cpp b/test/kinetics/kineticsFromYaml.cpp
index 210f9c18f9..703297ea82 100644
--- a/test/kinetics/kineticsFromYaml.cpp
+++ b/test/kinetics/kineticsFromYaml.cpp
@@ -299,11 +299,11 @@ TEST(Reaction, TwoTempPlasmaFromYaml)
         " rate-constant: [1.523e+27 cm^6/mol^2/s, -1.0, -100 K, 700 K]}");
 
     auto R = newReaction(rxn, *(sol->kinetics()));
-    EXPECT_FALSE(R->usesThirdBody());
-    EXPECT_EQ(R->reactants.at("O2"), 2);
+    EXPECT_TRUE(R->usesThirdBody());
+    EXPECT_EQ(R->thirdBody()->name(), "O2");
+    EXPECT_EQ(R->reactants.at("O2"), 1);
     EXPECT_EQ(R->reactants.at("E"), 1);
     EXPECT_EQ(R->products.at("O2^-"), 1);
-    EXPECT_EQ(R->products.at("O2"), 1);
 
     const auto rate = std::dynamic_pointer_cast<TwoTempPlasmaRate>(R->rate());
     EXPECT_DOUBLE_EQ(rate->preExponentialFactor(), 1.523e21);